“build an electric bike +electric bike battery”

Remove all metallic jewelry. This is another tip that I can give from experience. Arcing the contacts on your battery is not something you want to happen ever, and especially not against your bare skin. I’ve had it happen on my wedding ring and once even had a burn mark in the shape of my watch’s clasp on my wrist for a week. Now I take everything off.

I have now come to the conclusion however that i want a pack that is 48V and capable of running a 1000w motor for atleast an hour. I live in a hilly area, i use a downhill bike (heavy) and im not the smallest guy. Im feeling a bit insecure about putting too many cells in parallel. Through the years i’ve read that the consesus is that more than 4 cells in parallel is a risk. Since a 13S4P pack is about 12Ah (with good batteries) i was wondering if you had any input on how i should move on?

But what if you didn’t have to compromise? What if you could build your own ebike battery to your exact specifications? What if you could build a battery the perfect size for your bike, with all of the features you want, and do it for cheaper than retail? It’s easier than you think, and I’ll show you how below.

When it comes to lead acid batteries for ebike use, you’ll generally be looking for what’s called a “sealed lead acid” or SLA battery. SLAs come sealed in a hard plastic case and can be turned in any orientation safely without leaking acid. This makes them appropriate for ebike use. Wet cell lead acid batteries, like many car batteries, would leak dangerous acid if turned on their side or upside down, making them a bad idea for use on an electric bicycle, which is a lot more likely to get knocked over than a car. Remember to stick with SLAs – not wet cell lead acid batteries – for electric bicycle use.

The BMS is for 7S, I connect B1+, B2+, B3+, to the negative of the first serie. B4+ is connected to the positive of the first serie, B5+ positive of 2nd serie, B6+ positive of 3rd serie, B7+ positive of 4rd serie.

Thank you for the article! I am currently making a battery for an electronic skateboard, so I need the layout to be as thin as possible to allow ample room underneath the deck. Currently, I have 6 packs of 3 cells welded in parallel, and would eventually like to create a battery which is 9 cells long, 1 wide, and 2 high, for 18 in total (the two packs of nine would then be welded in series). I am wondering if I could be able to make 2 battery packs by welding 3 of my current 3 cell packs together in parallel to make a long, yet skinny pack, and then welding both packs of nine in series using the alternating system. Essentially, I would be creating a pack that would look like 3 of the ones you show above when making your first series connection. Let me know what you think, and thank you!

Sorry if this has been asked already but there are a ton of comments to wade through. Ten individual 18650 cells in series at a nominal voltage of 3.6 Volts would give me 36 volts. Assuming they are 2500 mAh a piece, then if I put 4 of these 10 cell in series packs together in parallel I would have a 10 Amp Hour battery correct? The same applies if I were to wire a pack together with 10 “4p” cells together in series. I’m trying to determine what the benefit of 10s4p over I guess what would be “4s10p”.

I love this company! The staff are friendly, helpful, and respond to email within hours. Their DHL shipping option is phenomenal – I received my order in two days. This is my first choice e-bike part supplier. Well done – keep up the great work!

Lithium Iron Phosphate is currently the most common lithium battery used in Ebike applications. It is considered the most stable lithium battery type available today (low risk of fire) and has a reasonably high life expectancy of over batteries for electric scooters canada charges.

1. Eligibility: Sweepstakes (the “Sweepstakes”) is open only to those who sign up at the online sweepstakes page and who are at least 18+ years old at the time of entry. The sweepstakes is open to the legal residents of the Contiguous USA and Canada and is void where prohibited by law. Employees of Electric Bike Technologies LLC (the “Sponsor”) their respective affiliates, subsidiaries, advertising and promotion agencies, suppliers and their immediate family members and/or those living in the same household of each are not eligible to participate in the Sweepstakes. The Sweepstakes is subject to all applicable federal, state and local laws and regulations. Void where prohibited.

Wear gloves. Work gloves, mechanic gloves, welding gloves, even latex gloves – just wear something. High enough voltage can conduct on the surface of your skin, especially if you have even slightly sweaty palms. I’ve felt the tingle enough times to always wear gloves now. In fact, my pair of choice for battery work are some old pink dish gloves. They are thin and provide great dexterity while protecting me from short circuits and sparks.

Where things can get a bit dicey is in charging batteries that are parallel connected. If you leave the batteries in parallel while charging, then the charger current will get shared between the batteries and you can be sure that they are always at the same charge level. However, that does mean one of the batteries will be getting charged through the discharge port, and depending on the specific BMS circuit it may not have overcharge protection on the discharge wires.

Make sure to consult the wiring diagram for your BMS, because some BMS’s have one more sense wire than cells (for example, 11 sense wires for a 10S pack). On these packs, the first wire will go on the negative terminal of the first parallel group, with all the rest of the wires going on the positive terminal of each successive parallel group. My BMS only has 10 sense wires though, so each will go on the positive terminal of the parallel groups.

Now you have the required specs on the pack, namely its voltage and capacity, so it’s a matter of finding one that meets your budget and weight restrictions. To a first order, for a given voltage and capacity, NiCad will cost twice as much as lead acid but come in at half the weight, NiMH will be 30% lighter and more expensive than NiCad, and lithium will be twice the cost of NiMH and a further half the weight again.

The last step of wiring the BMS is to add the charge and discharge wires. The pack’s positive charge wire and discharge wire will both be soldered directly to the positive terminal of the 10th parallel group. The negative charge wire will be soldered to the C- pad on the BMS and the negative discharge wire will be soldered to the P- pad on the BMS. I also need to add one wire from the negative terminal of the first parallel group to the B- pad on the BMS.

This makes sense. Yes, it would be possible. You could wire balance connectors and extra discharge plugs to make three packs out of your one 13s pack, such as two 6s packs and a 1s, or two 5s packs and a 3s, etc. Then you’d charge each one, one at at time, using your imax B6 charger. It would take a while, but that’s how you’d do it. Just be careful to not get your connectors confused, as you’ll have three sets of balance wires and three sets of discharge wires.

Electric bikes in the UK tend to come with either Lithium Ion (Li-Ion) or Lithium Polymer (LiPo) batteries. In China, on the other hand, lead acid batteries are still the most common ones used. In 2014 – according to the China Bicycle Association / IdTechEx  – 35 million eBikes were sold on the Chinese market, and just 2.8 million of them had lithium battery.

Many retailers suggest charging the battery at least once a month if the bike is not ridden much, and say that the more the bike is ridden, the stronger the battery will be. All batteries, though, will deteriorate in time and they will need to be replaced and disposed. When that time comes, it’s best to ask your local retailer how to dispose of the battery, but bear in mind that local authorities should provide recycling and disposal facilities.

Alternately, you can separate the batteries and charge each with its own charger, but then you have some small risk of reconnected the batteries when one is charged and the other is flat, if for some reason one of the batteries didn’t get charged up properly. We usually recommend leaving the packs parallel connected at all times.

8. Rights Granted by you: By entering this content you understand that Electric Bike Technologies LLC, anyone acting on behalf of Electric Bike Technologies LLC, or its respective licensees, successors and assigns will have the right, where permitted by law, without any further notice, review or consent to print, publish, broadcast, distribute, and use, worldwide in any media now known or hereafter in perpetuity and throughout the World, your entry, including, without limitation, the entry and winner’s name, portrait, picture, voice, likeness, image or statements about the Sweepstakes, and biographical information as news, publicity or information and for trade, advertising, public relations and promotional purposes without any further compensation.

11. Disputes: THIS SWEEPSTAKES IS GOVERNED BY THE LAWS OF United States AND PA, WITHOUT RESPECT TO CONFLICT OF LAW DOCTRINES. As a condition of participating in this Sweepstakes, participant agrees that any and all disputes which cannot be resolved between the parties, and causes of action arising out of or connected with this Sweepstakes, shall be resolved individually, without resort to any form of class action, exclusively before a court located in PA having jurisdiction. Further, in any such dispute, under no circumstances will participant be permitted to obtain awards for, and hereby waives all rights to claim punitive, incidental, or consequential damages, including reasonable attorneys’ fees, other than participant’s actual out-of-pocket expenses (i.e. costs associated with entering this Sweepstakes), and participant further waives all rights to have damages multiplied or increased.

Battery: 36V 8AH lithium battery. Power: 250W. The frame folds via a 2 part locking mechanism which ensures the catch safely remains locked when the bike is in use and can be operated with one hand fo…

Yea lead acid is a great way to cheaply get into ebikes and test new motor/controller combinations. Keep in mind though that your performance will increase when you switch to lithium. It’s easy to do though, as the bike doesn’t care what chemistry it receives, it just sees volts and amps. Good luck!

LiMn was by far the most common chemistry in cheap (and expensive!) built up electric bikes for a long time. It’s a cheap, light, safe chemistry. The problem is low C, but much more importantly short life. And not just a short number of cycles but a short shelf life as well. Losing 20% capacity a year even if you don’t use the battery much leads to a lot of expense and warranty claims. LiNiCoMn has the same low cycle life, light and cheap characteristics, but it seems to have a longer shelf life and a slightly higher C.

SLA-Sealed Lead Acid. Deep-cycle electric wheelchair batteries. Nobody pedals a wheelchair, so their bulk and weight were not an issue, but their low price keeps them as the battery of choice for wheelchairs and mobility scooters for the elderly. For a bicycle, the industry was on a constant lookout for something better.

For BMS’s, the highest quality ones come from a company called BesTechPower but they are more expensive. I have mostly used BMS’s from AliExpress. I’ve linked to a few examples of BMS’s I’ve used in the article above.

Battery chargers for electric bike batteries need to be specific for that voltage and type of battery. Lead batteries need a charger that trickle charges when finished, while lithium battery chargers do not trickle charge. E-Bikekit batteries are sold with the correct charger that matches the voltage and type for that battery.

For a 24V 7s pack, I’ve used this BMS a few times and been quite happy with it: http://www.aliexpress.com/item/7S-Li-ion-Lipo-Batteries-Protection-Board-BMS-System-24V-29-4V-20A-Continuous-Discharge-350W/32336397316.html

Safety disclaimer: Before we begin, it’s important to note that lithium batteries inherently contain a large amount of energy, and it is therefore crucial to handle them with the highest levels of caution. Building a DIY lithium battery requires a basic understanding of battery principles and should not be attempted by anyone lacking confidence in his or her electrical and technical skills. Please read this article in its entirety before attempting to build your own ebike battery. Always seek professional assistance if needed.

One other unrelated question: Do commercially available eBike batteries generally use off-brand cells for their assembled batteries to bring cost down, or similar to the cells, do reliable eBike companies use name-brand cells and off-brand internet vendors use off-brand cells?

“scooter batteries 36v +electric bike batteries for sale”

This pattern continues until we’ve got all 10 parallel groups connected. In my case, you can see that the first and last parallel groups aren’t welded on the top side of the pack. That is because they are the “ends” of the pack, or the main positive and negative terminals of the entire 36V pack.

That’s a good option. You’ll notice about a 30% increase in power, as well as a 30% increase in speed. Your motor can certainly handle it, the question is if your controller can. Make sure it’s rated for 48V or you’ll need to swap in a different controller.

For any other case, lithium batteries’ advantages greatly outweigh SLAs. Of course, for your specific ebike you might have other reasons that could sway you either way. At the end of the day, your ebike is all about you. I hope this information helps you make the right choice for your own battery needs.

The spacers you linked to make battery building a bit easier as you can set it up modularly, but as you indicated, they add a good amount of volume to the battery. I like to make my batteries as small as possible so I rarely use them. When I do, I use these ones, but it’s not very often.

I’m planning on building a 10S12P pack for usage on a custom DPV (Diver Propulsion Vehicle). For packaging purposes, it would be best for me to split the battery pack in several battery modules instead of a single block of cells.

The watts (power) the battery can provide is totally dependent on the type of cells and the BMS rating. So until I know more about your cells, I can’t help you. But for an example, imagine you used cells that were rated at 5A each. 7p x 5A = 35A total power capacity. 35A * 24V = 840 watts, the total amount of power your battery can handle. But now let’s assume you used a 20A BMS, meaning the BMS can only handle 20A continuously. That’s your limiting factor, so your new total battery maximum power is 20A * 24V = 480 watts. Now just substitute the actual current rating of your cells and BMS to solve for your battery’s power capacity.

The article was extremely informative, thank you. I’ve found everything but am struggling with good cells. At Aliexpress there are many choices but I’m struggling to get near the $2/cell mark you mentioned as a limit for decent cells and still find performance criteria of a good battery (or at all). So far I’ve found NCR18650B but it appears to have a 2C discharge rating for a 3400mA cell. At 4P this is more than enough but seems low for LiIon so I wonder if it is good? The price is $163 shipped to USA for 10s 4p 40 pieces to make 36v 13.6Ah. After adding shrink wrap, BMS and nickle strips I’m at $213 before buying a spot welder ($200). I can buy on the same site a 36v 15Ah Li Ion pack for $248. https://www.aliexpress.com/item/US-EU-No-Tax-DIY-lithium-18650-battery-pack-15AH-36V-Electric-Bike-battery-for-36V/32757165516.html?spm=2114.13010208.99999999.274.JmcpBS

Amazing article, just what I needed. Have been doing LOTS of research but have struggled to find any real answers on which charger I should buy for my homemade battery. I am making a 48V 13s4p battery with a BMS (with balancing) like yours but am stuck as to whether I need to buy a normal bulk charger or a ‘smart charger’ that will balance the battery. My question is will the BMS balance the battery on its own or will I need to get a charger that balances also?

Battery manufacturers are continuing to research for developments in dozens of battery chemistries, and a couple of years ago, a big improvement to LiPo/LiCo chemistries began to be produced. A high-Cobalt cathode (LiCo) provides very good power density, but how can we make it more stable and reliable? Here’s a quote from batteryuniversity.com

That’s exactly correct. You’d start by welding 10 parallel groups of 4 cells each, then you’d connect those 10 parallel groups in series to make one rectangular battery. I’ve done many 10s4p packs just like that for 36V 10ah ebike batteries.

After writing my question, I did more research on these cells regarding overcharging and over-discharging and I see where you’re coming from regarding not having connections between the parallel cell blocks to smooth out differences between individual cells. So as a permanent installation, it’s not going to work. However, I’ve had another thought, which I’ve put at the final paragraph.

Recently the federal goverment has been cracking down on the shipping of lithium batteries. For the vendor, it means that they must have Hazardous Materials (hazmat) shipping and pay hazmat charges, and only can ship an officially tested hazmat-compliant battery. This adds considerably to the cost of lithium batteries, and makes it even harder to find an ebike dealer, who will sell you any lithium battery pack that they can affordably source.

I’ve been reading a bit about how Batterybro.com makes sure to test there batteries are genuine, and how it seems they still get a lot of fake batteries from China. When you buy on Aliexpress.com how to you know and make sure the batteries you buy are genuine? there’s a lot of sellers how did you find yours?

Why does this formula work? Think about it: heat shrink (unless stated otherwise) usually has a 2:1 shrink ratio, so if I need something with less than twice the circumference (or perimeter rather, since my pack isn’t really a circle) of my pack. Since large diameter heat shrink is quoted in half circumference (flat width) sizes, and I want heat shrink with a circumference of batteries electrical bit more than the perimeter of my pack, then I know I need the half circumference size to be a bit more than half of my pack’s perimeter, which is equal to the height plus the width of my pack.

Oh, one last thing. If you have a poorly formed connector or the wires are fraying, that can increase resistance and cause a voltage drop that might trip a cutoff condition. Just another thing to check for.

The exact amount of range you’ll get per battery and motor varies greatly and depends on factors like terrain, speed, weight, etc. Suffice it to say though that if you double your current battery capacity, you’ll see an approximate doubling of your range as well.

I did not intend for the timeline to reflect anything other than what I recall seeing as E-bike battery packs. Some chemistries have been around a long time before they were used by a significant number of E-bikers.

“electric moped battery _electric car batteries”

You’re absolutely right that doubling the capacity of the battery by running two packs in parallel will essential halve the load on each pack, but I still don’t think it would get it down to the level that you could rely on compression fit spring contacts to safely carry that current, let alone the balance issue of not having the 4 groups individually paralleled at the cell level.

You’ll also notice in the following pictures that my charge and discharge wires are taped off at the ends with electrical tape. This is to keep them from accidentally coming in contact with each other and short circuiting the pack. A friend of mine recently tipped me off to another (and probably better) option to prevent shorts: add your connectors to the wires first, then solder them onto the pack and BMS. Doh!

Typically you can expect somewhere between 25 and 70 miles of travel on a single charge of an ebike. If you’re riding hard on full power expect less; manage your battery life well and you could get more.

The Panasonic NCR18650PD cells can be purchased at Fast Tech dot Com, who reliably processed and shipped my transaction. Good prices, too, from this Chinese-based vendor. I “tested the waters” by buying just 4 cells first and will certainly be buying more from them. I’d like to make my own e-bike pack with these cells and further inquired to AllCell to see if I could obtain one of their PCM blocks. Unfortunately, they will only sell these on bulk wholesale basis to established pack-building businesses. The DIY pack builder will have to explore other options.

I would advise against connecting one battery to the other’s charging port. That charging port, as you correctly stated, is wired to a charging circuit on the BMS which is usually meant to take 5A max, sometimes less, whereas the discharging side of the BMS usually puts out at least 15A, sometimes much more. You can easily fry your BMS by connecting a second battery to its charge port.

I’m mostly kidding, but if you use cells that are rated for more current than you’re trying to pull from them, you’ll create a lot less waste heat and both options will be perfectly fine and healthy for the battery.

In the rush to upgrade from lead acid to the latest NiMH and lithium packs, it seems that most companies forgot about the old venerable Nickel Cadmium battery as a suitable option for ebikes. Although they are somewhat heavier than the NiMH and lithium options, they are still a substantial weight savings over lead. NiCd packs have had a solid and proven track record in demanding rechargeable battery applications.

I would not recommend trying to use a 36V charger. The voltage will be way too high and damage either the charger, battery, BMS or all three. Always use a charger that is matched to your pack’s actual charge voltage, which in your case is 22.2V DC.

36V 10ah Lithium battery (Included with the battery is the charger and mounting Bracket). Standard 26 in Front Wheel 500w brushless motor hub (works with V-brake or disc brakes). Pedal Assistance syst…

i noticed that bms installation is different (as i guess) from the video (https://www.youtube.com/watch?v=rSv9bke52eY&index=10&list=LLDXj2cy8mbQoc0dz3RO3zFw) i have watched before. In this video bms wires were connected on the negative poles of batteries lifepo4. In my amateur opinion i could not understand how we organize BMS connections for my 13s pack. if you illuminate me, i will be preciated.

When it comes to lead acid batteries for ebike use, you’ll generally be looking for what’s called a “sealed lead acid” or SLA battery. SLAs come sealed in a hard plastic case and can be turned in any orientation safely without leaking acid. This makes them appropriate for ebike use. Wet cell lead acid batteries, like many car batteries, would leak dangerous acid if turned on their side or upside down, making them a bad idea for use on an electric bicycle, which is a lot more likely to get knocked over than a car. Remember to stick with SLAs – not wet cell lead acid batteries – for electric bicycle use.

One of the easiest ways to increase the current handling capability and range is to put two or more batteries in parallel. In general, with lithium batteries of the same nominal voltage, this is no problem. It is perfectly fine to mix old and new lithium batteries in parallel, or even batteries from different manufacturers and with different capacities, so long as they are the same voltage. We stock a parallel battery joining cable to facilitate connecting packs this way. 

Something that’s worthy of note, is that “AllCell” is using a block of graphite/wax composite Phase-Change-Material (PCM) using a patented formula. If a single cell suddenly starts running hot, the heat is instantly spread out across the PCM block, which would prevent a thermal runaway event. According to a recent press-release:

Now I’ve got all of my pack sealed in heat shrink with my wires exiting the seam between the two layers of shrink wrap. I could have stopped here, but I didn’t particularly like the way the shrink fell on the wire exit there, from a purely aesthetic standpoint. So I actually took a third piece of shrink wrap, the same size (285 mm) as that first piece and went around the long axis of the pack one more time to pull the wires down tight to the end of the pack.

1. The extra http://electricbikebatterys.com that the battery could output isn’t wasted, it’s just sort of a safety factor. It means you aren’t stressing the battery to its limit. Also, batteries only get their full rated capacity at lower discharged. So you’re more likely to get the full capacity now than if you actually pulled 50A out of it.

I’m not sure what cells exactly you’ve got there, but a good replacement cell (assuming it has similar specs to your cells, which you’ll have to confirm) could be the Samsung 26F cell. It’s a good quality economical battery cell. I’ve gotten them from here and had great experiences with the vendor: Samsung 26F 18650 lithium battery cells

I KNOW ALL YOU “DO-IT-YOURSELF” E-BIKE AND POWERWALL BUILDERS OUT THERE ARE LOOKING FOR AFFORDABLE AND HIGH QUALITY 18650 CELLS. HIGH DRAIN MEANING THESE ARE RATED FOR 10A CONTINUOUS AND 20A MAX PER C…

22f cells are quite low capacity and not very strong. They will work for an ebike (and are about the cheapest good quality cells out there) but they aren’t optimal. You’ll end up with a larger and heavier pack as compared to more energy dense cells like Panasonic 18650pf or Sanyo 18650ga cells.

Do you by any chance have some spare parts you can swap in? A spare controller would you let you know if the controller is faulty and tripping early. Another battery would show you if the problem was battery related.

Alibaba.com offers 176,519 electric bike battery products. About 29% of these are electric bicycle, 22% are rechargeable batteries, and 8% are electric bicycle battery. A wide variety of electric bike battery options are available to you, such as 36v, 24v, and 48v. You can also choose from lithium battery, lead acid battery. As well as from 10 – 20ah, 21 – 30ah, and > 40ah. And whether electric bike battery is paid samples, or free samples. There are 176,478 electric bike battery suppliers, mainly located in Asia. The top supplying countries are China (Mainland), Taiwan, and Vietnam, which supply 99%, 1%, and 1% of electric bike battery respectively. Electric bike battery products are most popular in North America, Western Europe, and Northern Europe. You can ensure product safety by selecting from certified suppliers, including 39,164 with ISO9001, 14,565 with Other, and 6,300 with ISO/TS16949 certification.

48 volt 1500 watt motor 48 volt 16.5 amp Samsun cell high quality battery 2amp charger, charges in 6 hours plus battery has USB port to charge your phone Top speed 35mph high torque Comes with every t…

“battery for electric scooter -e-bike battery”

You mentioned that you made a discharger from halogens. Is there any reason not to just use a couple power resistors in parallel, like 2×25 ohm, 100w for a 13s6p pack? Do you know why it’s helpful to take it easy on the pack for the first couple cycles?

Lithium Ion electric bike batteries are ideal for those that plan to ride longer distances and or more frequent trips. The commuters dream battery, lithium batteries can stand two complete 100% discharges a day for years. Discharging the battery half way riding to work or school, then parking all day at half charge does no damage to a lithium electric bike battery. So the urgency to recharge immediately is not like SLA’s. Since discharging to 100% empty does not significantly harm lithium electric bike batteries, the usable range of the lithium electric bike battery is roughly double that of SLA’s. In typical electric bike use, Li-Ion batteries last from two to four years. Proper storage of Lithium Ion batteries is important when the electric bike will not be used for more than a few weeks. Unplug the battery from the electric bike, charge fully, and then store in a cool but not frozen, dry place.

I just found your article, and as if it were destiny, this is exactly what I am trying to do (build a battery pack with BMS, and charge with charger). I am new to this, however, and have a question or two…

Grew up in Los Angeles California, US Navy submarine mechanic from 1977-81/SanDiego. Hydraulic mechanic in the 1980’s/Los Angeles. Heavy equipment operator in the 1990’s/traveled to various locations. Dump truck driver in the 2000’s/SW Utah. Currently a water plant operator since 2010/NW Kansas

One other unrelated question: Do commercially available eBike batteries generally use off-brand cells for their assembled batteries to bring cost down, or similar to the cells, do reliable eBike companies use name-brand cells and off-brand internet vendors use off-brand cells?

The only thing left to do at this point is to add the connectors, unless you did that before you soldered the wires on, which I actually recommend doing. But of course I didn’t do that, so I added them at this step, being careful not to short them by connecting only one wire at a time.

The spacers you linked to make battery building a bit easier as you can set it up modularly, but as you indicated, they add a good amount of volume to the battery. I like to make my batteries as small as possible so I rarely use them. When I do, I use these ones, but it’s not very often.

36V 10ah Lithium battery (Included with the battery is the charger and mounting Bracket). Standard Fat Wheel 26 in by 4in Front Wheel 500w brushless motor hub (works with disc brakes). Pedal Assistanc…

Hi Micah, I have been studying your how to build an bike battery, and enjoyed all the tips. I have been having a bit of difficulty figuring out the wiring portion of the construct however. For example, you talk of C, B and P pads and wires you solder to the top and bottom of the pack; the yet don’t put arrows to or refer to their colors for easy identification. The charge and discharge instructions for connecting are gone over rather fast with little for us to identify with exactly where to attach to, etc. Could you revisit your post here and include some baby steps for those who can’t follow the reference instructions you give for wiring the BMS?

Yes, I’ve seen this problem. Homes that have only a 10A circuit breaker are often not enough for these welders. The room I wanted to use mine in had a 10A, so I switched it for a 20A breaker at the breaker box and now it works fine.

What does that mean?. Well, it is like having another fit bicycle rider helping you pedal, but without their weight. No matter how hard your hills, or heavy your bike is, this motor will always work t…

Most electric bicycle batteries fall into the 24V to 48V range, usually in 12V increments. Some people use batteries as high as 100 volts, but we’re going to stick to a medium sized 36V battery today. Of course the same principles apply for any voltage battery, so you can just scale up the battery I show you here today and build your own 48V, 60V or even higher voltage battery.

Because of problems with quality and weight, lead acid batteries are not common in the rest of the world. In Europe, for example, acid lead batteries represent less then one per cent of the total; while 96.5 per cent is taken by Li-Ion and two per cent by LiPo (source: Greenfinder market report).

Do you think it is the BMS or the controller that is cutting out beyond a certain load or something else completely? As far as I am aware the battery is fully charged and balanced (I even left it charging for 2 days once as I read that it can sometimes take this long to balance the cells!).

To calculate the max amps the battery can deliver, you have to know the max amps of the cells you used. For example, Panasonic 18650pf cells can deliver 10A continuous, and I used 3 cells in series in this battery, so the battery can deliver 3 x 10A = 30A. However, you also need to know how much current the BMS can deliver. If I put a 15A continous BMS on this pack then that would be the “weakest link” so to speak, meaning the pack with the BMS could only deliver 15A continuous.

When it comes to welding your parallel groups in series, you’ll have to plan out the welds based on your welder’s physical limits. The stubby arms on my welder can only reach about two rows of cells deep, meaning I will need to add a single parallel group at a time, weld it, then add another one. If you have handheld welding probes then you could theoretically weld up your whole pack at once.

Be aware the NCA chemistry can be had in a low-amp and high amp version. By having a single 3100-mAh cell inside the cylinder, the internal volume is maximized (good for laptops and cordless drills by providing the absolute longest run-time). But…by putting a couple of cell-divisions inside that same cylinder with a parallel connection, the internal volume is reduced to 2900-mAh, but the amp producing ability is doubled, with the NCA chemistry being advertised as capable of 10A per cell, which is roughly a C-rate of a continuous 3C.

1C charging is too high for most Li-ion. It’s too much to ask for right now, to be able to charge an entire pack in one hour. It can be done, but it’s not healthy for the cells. Aim for 0.5C at the most. I usually don’t go past 0.3C on charging.

Lead acid batteries are the least expensive and heaviest battery option. They have a short cycle life if used regularly in deep discharge applications. For electric bikes, the most common setups use 12V bricks of either 7Ah or the larger 12Ah capacities, series connected to form 36V or 48V packs. Because of the Peukert effect, the 7Ah gel cell usually delivers about 4 amp-hours of actual capacity, while the 12Ah lead acid packs will deliver approximately 8 amp-hours. So keep this in mind when comparing a lead acid pack to one of the NiCd, NiMH, or lithium replacements. We do not offer lead acid batteries or chargers, but they are not hard to find.

Now you have the required specs on the pack, namely its voltage and capacity, so it’s a matter of finding one that meets your budget and weight restrictions. To a first order, for a given voltage and capacity, NiCad will cost twice as much as lead acid but come in at half the weight, NiMH will be 30% lighter and more expensive than NiCad, and lithium will be twice the cost of NiMH and a further half the weight again.

Good question. The answer comes down to the difference between “nominal voltage” and “actual voltage”. LiFePO4 cells are nominally called 3.2V cells, because this is their voltage in the middle of their discharge curve, at about 50% discharge. They actually charger to a higher voltage though, about 3.7V per cell. That means that you need a charger that has an output voltage of 3.7V x 6 cells = 22.2V DC. This is going to be a bit harder to find because most LiFePO4 packs come in multiples of 4 cells, (4, 8, 12, 16 cells, etc) so finding a charger for a 6S pack might take some searching. This charger is a good quality one meant for 8 cells (output voltage of 29.2V DC) but if you put a note in the purchase order, the seller can adjust the output for 6 LiFePO4 cells (22.2V DC). http://www.aliexpress.com/store/product/aluminum-shell-24V-29-2V-3Amper-Lifepo4-battery-charger-high-quality-charger-for-8S-lifepo4-battery/1680408_32274890691.html

The Panasonic NCR18650B cells you have are very good quality cells. I used similar cells also made by Panasonic, but mine are the NCR18650PF (not B). The difference is that yours have more capacity (mine are 2900mAh, yours 3400mAh) but yours have a lower constant current draw rating. I don’t remember what it is off the top of my head, but I don’t think it’s much more than 5A per cell. So just make sure that you either use enough cells in parallel and/or limit your controller to not draw more power than the cells can handle. Check the cell specification sheet which you can find on Google somewhere to ensure that you are staying within the cells’ limit.

More than likely this problem is BMS related. The BMS usually batteries for e bikes in that scenario for one of two reasons: 1) The load pulled by the controller is too high for that BMS, or 2) one or more cells are weak or damaged and when the load is applied strongly, it causes the voltage of that parallel group to drop below the LVC of the BMS.

Sizing a bike correctly is important for pedaling efficiency and safety. Fitting a bike involves many factors. However, the basic considerations before buying a bike include frame size, seat height, and…

Hi Danl, that sounds like a very high power motor. Most consumer ebikes are in the 36V-48V range, so if your motor is advertised as being rated for those higher voltages then it’s definitely a more serious motor. If you’re looking for a ready-built and relatively inexpensive battery, then something like this might work for you, though I haven’t personally used that battery. You can of course build your own battery just like I did in this article, and that way you’ll be sure to get exactly what you’re looking for. The AH’s required will depend on the quality of the battery. A batter rated for higher current will require fewer AH’s than a lower quality battery. I’d aim for at least 20AH, if not more on a motor of that size. It’s going to eat your battery quickly, so you’ll want more capacity to be able to ride longer.

LiFePO4 is currently widely available for purchase as e-bike packs complete with BMS on ebay and other online merchants. Mostly it is sold by small companies. Also, most of the commercially available e-bikes powered by lithium batteries are using the LiFePO4 chemistry.

2. Agreement to Rules: By participating, you agree to be fully unconditionally bound by these Rules, and you represent and warrant that you meet the eligibility requirements set forth herein. In addition, you agree to accept the decisions of Electric Bike Technologies LLC, as final and binding as it relates to the content. The Sweepstakes is subject to all applicable federal, state and local laws.

I use my welders on 220V, though 110V versions are available. If you have access to 220V in your home (many 110V countries have 220V lines for clothes dryers and other high power appliances) then I’d recommend sticking with 220V. In my experience the 110V models seem to have more problems than their 220V brothers. Your mileage may vary.

A high quality USA battery manufacturer by the name of “Allcell” constructs packs consisting of 18650 cells (cylindrical cells that are 18mm diameter and 65mm long) and uses high tech packing materials to spread out the cells and thus the pack gets a longer life. This is the pack of choice in many high end commercially available ebikes including the Optibike, the Picycle, and the Hanebrink. (click on each to see article on that electric bike). The 18650 battery cell format is mass-produced for laptop computers and cordless tools.

You can use any connectors you like. I’m a big fan of Anderson PowerPole connectors for the discharge leads. I used this other connector that I had in my parts bin for the discharge wires. I’m not sure what that type of connector is called, but if someone wants to let me know in the comments section then that’d be great!

“batteries for electric bicycles _ebike battery”

Lastly, there’s a small chance that it’s just a faulty BMS. This method is annoying, but if all else fails then you can try swapping out the BMS. More than likely though, the BMS is doing it’s job because one of the cutoff conditions is fulfilled https://en.wikipedia.org/wiki/Electric_bicycle it’s just trying to protect the pack.

Lithium batteries (with the exception of RC LiPos) last much longer than lead acid batteries. LiPo batteries are usually only rated for a few hundred charge cycles but LiFePO4 batteries keep going after thousands of charge cycles. Every manufacturer rates their batteries differently, but most LiFePO4 ebike batteries will be rated for between 1,500 to 2,200 charge cycles.

First thing is regarding the cells – I have just order some Panasonic 18650PF like yours by chance (I was looking for Samsung). The delivered cells were made and charged in 2014, and the measured voltage now is around 3V (+/- 0.1v). So the voltage is basically the same for all of them but there are old, I think, even thaw never used and stored in a warehouse.

You’ll see two dots where the weld was performed. Test the weld by pulling on the nickel strip (if it’s your first time using the welder). If it doesn’t come off with hand pressure, or requires a lot of strength, then it’s a good weld. If you can easily peel it off, turn the current up. If the surface looks burnt or is overly hot to the touch, turn the current down. It helps to have a spare cell or two for dialing in the power of your machine.

Is it possible that the controller for this Rayos 600W (sorry thought it was 500W but it’s actually 600W) is inside the electric motor itself? I traced all wiring on the E bike but find no controller anywhere. Do you see anything majorly wrong with using a BMS to charge the cells but not discharge, as in sending the current from the battery directly to the controller / motor? I’ve been unable to find a BMS that can do 30A that isn’t very expensive. A side note, I was able to test amperage while riding and around 20A gets me 9 miles per hour, that is where my multimeter tops out! I’m 235 pounds. I’m guessing I need around 30A to get the 16 MPH I get now with the existing LiFePO4 battery pack.

Bigger is better! And I know a better way batteries should be made. I use 560 of the Panasonic 18650b battery cells with 3.4AH per cell, wich in the end gave me (7kwh battery ebike!), that’s more than 300+ miles battery range easy. And I’ve learned that these batteries can be assembled like Lego blocks instead and eliminate harmful heat from soldiering, and wastful glueing. The benefit is a battery pack that can have removable, repairable, and reconfigurable battery cells! Its called (battery blocs) patiented by Shawn McCarthy. Unfortunatly its not the cheap method and requires a 3d printer to make. It spaces the cells slightly apart for better air cooling. Mine are packed into 4 PVC tubes run either at 103.6v or 51.8v. I believe along with some experts that a BMS is not required and can cause battery cells to fail early!, and a proper set voltage monitor and regulator prevents over discharge damage and you need to a timer and monitor the cell voltages with cell monitors while charging. Cooling setup would be a pluse to extend life. That’s all for now, best luck to all battery builders.

This had led me to believe that if there is too much load being exerted on the bike (i.e. the current being drawn from the battery is too high) then either the BMS or the controller trips and cuts out. However I am reluctant to believe that the BMS is causing the trouble as it has a 40A rating on it (this link shows the exact BMS) http://www.aliexpress.com/item/Electric-motor-car-13S-48V-40A-BMS-lithium-ion-battery-BMS-Used-for-48V-20Ah-30Ah/32484213150.html?spm=2114.13010608.0.62.evx6sX .

There are many different types of lithium ebike batteries to choose from. I’ll give a short summary of the different types of electric bicycle specific lithium batteries here, but you can get a more detailed description as well as the pros and cons of each type of lithium battery in my article Not All Lithium Batteries Were Created Equal.

Finally, have you used the type of spot welder shown with hand held probes? Can see the benefit of greater reach, but do you know if this gives as neat a result (my spot welder there is a very firm press up to activate, hence the discharge only occurs when the tips of the welder are pressing the strip firmly against the top of the cell so i assume ensuring a tight weld)

One of the first advantages of lithium batteries is their small size. You can fit a lot of lithium on a bicycle frame. This alone can give your ebike some seriously impressive range. Two or three mid to large capacity lithium batteries could easily fit on one ebike, giving potential ranges of 100 miles (160 km) or more. I guess this would be great for people that don’t mind sitting on their bike for three to five hours at a time, or that for some reason don’t want to charge up for weeks (hey, when riding your ebike through a zombie apocalypse, the last thing you want to be doing is searching for an outlet).

These lists, updated hourly, contain bestselling items. Here you can discover the best Adult Electric Bicycles in Amazon Best Sellers, and find the top 100 most popular Amazon Adult Electric Bicycles.

That might of sounded confusing, so let’s talk in real numbers. My pack is about 70 mm high and about 65 mm wide. That means that half of the perimeter of my pack is 70+ 65 = 135 mm. So I need some heat shrink tubing that has a flat width (or half circumference) of between 135 to 270 mm, or to be safer, more like between 150-250mm. And if possible, I want to be on the smaller end of that range so the heat shrink will be tighter and hold more firmly. Luckily, I have some 170mm heat shrink tube which will work great.

HERE ARE 100 GENIUNE LG LGDAS31865 18650 2200MAH CELLS. YOU CAN’T FIND A BETTER DEAL THAN THIS. Capacity: 2200mAh. THE PHOTOS SHOW HOW WE GET THESE IN AND BREAK THEM DOWN. STOP GETTING RIPPED OFF AND …

48 volt 1500 watt motor 48 volt 16.5 amp Samsun cell high quality battery 2amp charger, charges in 6 hours plus battery has USB port to charge your phone Top speed 35mph high torque Comes with every t…

If I regroup my 12 paralled cells in 10 modules, can I then join these in series using single wires (one for neg, one for pos) between modules, instead of wiring each terminals of each cells like you are doing. Could this affect BMS and/or have any negative impact on cells balance?

7. Winner selection and notification: Winners of the Sweepstakes will be selected in a random drawing under the supervision of the Sponsor. Winners will be notified via e-mail to the e-mail address they entered the Sweepstakes with within five (5) days following the winner selection. Electric Bike Technologies LLC shall have no liability for a winner’s failure to receive notices due to winners’ spam, junk e-mail or other security settings or for winners’ provision of incorrect or otherwise non-functioning contact information. If the selected winner cannot be contacted, is ineligible, fails to claim the prize within 15 days from the time award notification was sent, or fails to timely return a completed and executed declaration and releases as required, prize may be forfeited and an alternate winner selected. The receipt by winner of the prize offered in this Sweepstakes is conditioned upon compliance with any and all federal and state laws and regulations. ANY VIOLATION OF THESE OFFICIAL RULES BY ANY WINNER (AT SPONSOR’S SOLE DISCRETION) WILL RESULT IN SUCH WINNER’S DISQUALIFICATION AS WINNER OF THE SWEEPSTAKES AND ALL PRIVILEGES AS WINNER WILL BE IMMEDIATELY TERMINATED.

My series connections are between each group of 3 parallel cells. So all the connections that go across the short side of the pack are parallel connections, and all the connections that run along the long end of the pack are series. It doesn’t always happen that way, but the shape of this pack forced that geometry.

You will find here all Li-Ion/LiFePO4 EBike battery packs and cells, battery management system(BMS). This category includes 12V~72V Li-Ion/LiFePO4 EBike battery packs and cells, EBike bottle battery, high power battery and high C-Rate cells, 4~24 cells in series Li-Ion/LiFePO4 bleeding balancing BMS and 5~13s smart BMS.

Battery chargers for electric bike batteries need to be specific for that voltage and type of battery. Lead batteries need a charger that trickle charges when finished, while lithium battery chargers do not trickle charge. E-Bikekit batteries are sold with the correct charger that matches the voltage and type for that battery.

The Panasonic 18650pf is a good cell, that’s the one I used here. I also like the Samsung 26F, though it’s a fairly low power cell, and the Samsung 29E which is a bit higher power cell. The Samsung 30Q is a fairly new cell that has good specifications but doesn’t have as long a life – everything is a trade-off.

For the record, I just wanted to add my experiences with LiFePO4. I built an ebike with 16 Headway 40160S cells one year ago (48 Volts, 16 AH). They are rated at 10C maximum continuous discharge. I have my controller set for a maximum draw of 30 Amps, well below their ratings. The first BMS killed a couple of cells, which I replaced. Then I switched to a Signalab BMS and the cells have balanced nicely ever since. I’m up to 120 charge cycles and over 1500 miles.

The controller that came with my ebike conversion kit just has the label ’48v 1000w’ on it and there are no other specifications anywhere to be seen. I have emailed the suppliers asking if I could have a full list of specifications for the controller but am yet to hear back from them.

Capacity: 20Ah. 36V 3A Charger. Lifecycle of single cell: >85% capacity after 1500 cycles, > 70% capacity after 3000 cycles. (<1C discharge rate and <1C charge rate). It will take about 7 hours to cha... craig it should not damage your controller. When you connect two batteries together in parallel it will actually extend the life of both batteries because you are not taking as much of a toll on them when discharging and hopefully not running them down as low. A better and simpler solution would be, as you said, to carry a second battery and just swap the connector from the old battery to the new one when the old battery is depleted. There are a few types of bottle batteries out there, I recommend googling “bottle battery” if you haven’t yet, you’ll likely find a few options. I don’t know if this is the same model as yours, but some common styles similar to your description can be found here and here. Most electric bicycle batteries fall into the 24V to 48V range, usually in 12V increments. Some people use batteries as high as 100 volts, but we’re going to stick to a medium sized 36V battery today. Of course the same principles apply for any voltage battery, so you can just scale up the battery I show you here today and build your own 48V, 60V or even higher voltage battery. Grew up in Los Angeles California, US Navy submarine mechanic from 1977-81/SanDiego. Hydraulic mechanic in the 1980's/Los Angeles. Heavy equipment operator in the 1990's/traveled to various locations. Dump truck driver in the 2000's/SW Utah. Currently a water plant operator since 2010/NW Kansas The answer is that, unless you are seriously budget or weight constrained, this would probably be a bad battery investment. It might fit the bill initially for your commuting needs, but then it doesn't really leave any reserve if you need to run some errands on the way home, or forget to charge it up one night etc. Even worse, as the battery ages over time the capacity drops. After a year your 8Ah battery is now only 7Ah, it's only barely able to do your daily commute, and the next year when it is just 6Ah you now need to carry the charger with you and top it up at work every day. Lithium chemistry is considerably more expensive than the “old school” lead acid chemistry. If you are buying a battery pack or a bike that already has a battery pack, be familiar with the chemistry that you’re buying. For example, its hard to find a good e-bike for under a thousand dollars with a decent-sized lithium pack. Lithium is pricey. Be realistic in your expectations when e-bike shopping on how much the electric bike will cost compared to what kind of range, performance, and life expectancy you will get out of a lithium battery pack. By entering the Sweepstakes you agree to receive email newsletters periodically from Electric Bike Technologies LLC. You can opt-out of receiving this communication at any time by clicking the unsubscribe link in the newsletter. Rechargeable Electric Bicycle Batteries 48V 20AH Lithium Ion Battery. These are 18650 cell based batteries (similar 18650 type cells are used in the Tesla car). Use it for ebike, scooter etrikes. Batt... 3. i saw 18650 and 26650 li ion batteries which are more powerful such as 6000 – 8000 mah. i think they are fake??? i need 48v 10ah or 20ah minimum i guess as a pack ??? your advices are important. thanks for all… The other thing to consider is that if you have one 48-volt 10-Ah battery putting out a measly 20 amps, you can add a second version of the same battery, wire them together in parallel, and you will have a 20-Ah pack with a 40-amp capacity, thus effectively doubling your range and doubling your amp output performance. [redirect url='http://bestelectricbikebattery.com//bump' sec='7']

“panasonic 18650 cells battery scooters”

Now http://bestelectricbikebattery.com got all the info you should need to make your own electric bicycle lithium battery pack. You might still need a few tools, but at least you’ve got the knowledge. Remember to take it slow, plan everything out in advance and enjoy the project. And don’t forget your safety gear!

If you don’t find that, there’s still a chance that it’s the problem, and that the cells simply rose up to a higher voltage and matched the others again once the load disappeared. But it also may be that the load is too high for the BMS. Do you have a cycle analyst? You could slowly increase the throttle and watch how much current you are drawing until the point of cutoff. If it’s well below 40A then you’ll know it’s not a high current cutoff.

My question for you is, if I just want to run a BMS for balance charge purposes only and want to wire the battery discharge directly to the motor how would I do that? Would that be a good solution as long as I monitor battery pack voltage during rides?

There are many different types of lithium ebike batteries to choose from. I’ll give a short summary of the different types of electric bicycle specific lithium batteries here, but you can get a more detailed description as well as the pros and cons of each type of lithium battery in my article Not All Lithium Batteries Were Created Equal.

You can actually buy an E-bike NMC pack right now, but it remains to be seen which retailer will prove to be the most reliable. An NMC pack will be about 25% smaller and lighter than an equivalent LiFePO4/LiMnO2 pack. The extensive testing done by Zero, Tesla, and Nissan gives us a great deal of confidence in the safe and effective use of NMC over the next year…

One of the first advantages of lithium batteries is their small size. You can fit a lot of lithium on a bicycle frame. This alone can give your ebike some seriously impressive range. Two or three mid to large capacity lithium batteries could easily fit on one ebike, giving potential ranges of 100 miles (160 km) or more. I guess this would be great for people that don’t mind sitting on their bike for three to five hours at a time, or that for some reason don’t want to charge up for weeks (hey, when riding your ebike through a zombie apocalypse, the last thing you want to be doing is searching for an outlet).

A recent quote from ES member SamTexas on claimed max C-rates: “…I have in front of me Samsung’s own Nickel (Manganese) 18650 cells….I have tested these cells at 3C continuous and they do deliver full capacity at that rate. Push it to 5C and they become hot and capacity is greatly reduced…“

Dang, I just realized what I did wrong. I had been thinking as I connected the sense lines it was arbitrary which end of the battery was B1 and which B13, but obviously it isn’t. B1 has to be the negative end and B13 has to be the positive end. Since I already cut the sense lines to length, I’ll need to put my replacement BMS on the opposite end of the pack.

When soldering these wires to the nickel strip, try to solder between two cells and not directly on top of a cell. This keeps the heat source further from the actual cell ends and causes less heating of the battery cells.

This is by far the most common lithium-ion chemistry used in electric bicycles. It is somewhat heavier than lithium polymer and the lithium-cobalt packs that are usually used laptops and consumer electronics, but is also safer. Most of the lithium manganese packs we have dealt with use rectangular steel canned cells and have good discharge capabilities. This chemistry holds its voltage better over the course of the battery discharge than Lithium Polymer, which tends to have a linearly declining voltage from 4.2 to 2.9 volts/cell during the course of the discharge, leading to a ebike that starts off feeling peppy and finishes feeling lethargic.

The nickel is surprisingly soft, which means you can use an ordinary pair of scissors to cut it. Try not to bend it too much though, as you want it to remain as flat as possible. If you do bend the corners with the scissors, you can easily bend them back down with your finger.

Lithium batteries made specially for ebikes often come with specific bicycle mounting points making them easy to bolt to the bike frame, seat post or rear rack. If you go with a different type of lithium battery without ebike specific mounts, you’ll likely have to put it in a bag on the bike, which is still a good option, and one that I even prefer sometimes. (Link to blog post of mine about center frame triangle batteries).

“electric bicycle battery case -lithium ion bike”

The last step of wiring the BMS is to add the charge and discharge wires. The pack’s positive charge wire and discharge wire will both be soldered directly to the positive terminal of the 10th parallel group. The negative charge wire will be soldered to the C- pad on the BMS and the negative discharge wire will be soldered to the P- pad on the BMS. I also need to add one wire from the negative terminal of the first parallel group to the B- pad on the BMS.

Actually, the protected cells aren’t a great option for ebike packs. The protection circuit on every cell can overcomplicate things, not to mention that it usually isn’t rated to handle the same current the cell could without a protection circuit.

1C charging is too high for most Li-ion. It’s too much to ask for right now, to be able to charge an entire pack in one hour. It can be done, but it’s not healthy for the cells. Aim for 0.5C at the most. I usually don’t go past 0.3C on charging.

2018 model Pedalease Estar MTB electric mountain bike 1000w or 1500w rear hub motor with option of 48v 10ah, 48v 11.6ah and 48v 17ah lithium battery. Motor: Pedalease 1000W or 1500w rear drive brushle…

For this reason I like to either add a second lock specifically through the handle of my lithium battery (if it’s a removable style battery) or permanently secure it to the bike so it isn’t removable at all. The second option is less convenient because it means you have to bring the charger to the ebike, but it’s a much more secure option if you find yourself locking your ebike in public often.

15. This promotion is in no way sponsored, endorsed or administered by, or associated with Facebook, Twitter, Youtube, Pinterest, LinkedIn or Google. You understand that you are providing your information to the owner of this sweepstakes and not to Facebook, Twitter, Youtube, Pinterest, LinkedIn or Google.

You told us what you wanted and now we’re delivering it. ShippingPass is our new subscription program designed to bring you unlimited 2-day free shipping for one year with no minimum order. Get what you need ― fast!

I’m a little worried that your batteries aren’t what you think they are. If they really are AA sized, which is rare in the lithium battery world, then they are not 3,000 mAh. Next, 10 cells in series is going to give you 36V, which is twice what your 18V drill is rated for. 5 cells in series and 2 in parallel would be a better method. I usually recommend a BMS but you can skip it if you have another way of diligently monitoring your cell voltages and then charging using an RC style balance charger like an iMaxB6 charger through an JST-XH connector.

Introduce Yukon Trail 2018 new model Xpedition Features: 350w motor Battery: Samsung lithium battery (light weight 5 lbs with case) Speed/Mileage: up to 20MPH, up to 28 miles per full charge (varies b…

If you are using 2.5AH cells then yes, it will be 5AH with a 2p configuration. If you use cells with higher capacity, like Sanyo GA cells that are 3.5AH, then you’ll have a 7AH pack with only 2p. Make sure your cells can handle the current that your electric scooter (and namely the controller) will try to draw from it.

The very first consideration when choosing a battery pack is ensuring that it can handle the current draw of your motor controller. If you have a 40A motor controller, but your battery is only rated to deliver 25A max, then either the BMS circuit will shut off the battery at full throttle, or the battery will be stressed and have reduced cycle life.  The converse, having a battery that has a higher current rating than what your controller will draw, is no problem at all. In fact, it can be quite beneficial. 

I am just trying to install a battery on a velomini 1 that I traded for. I don’t have a problem using the above battery as a hang on battery, but don’t know if it has the BMS in it or if my current charger would charge it. It is pretty cheap.

I have found this BMS which is cheap (necessary for my project) and it is shipped from the UK. Because it is so cheap do you think that it may not be balancing? http://www.ebay.co.uk/itm/400984825723?euid=0502c7e2b2c744ec8857879d65d46e08&cp=1

When it comes to buying your cells, you might be able to find a local source, or you can order them straight batteries for electric scooters replacement Asia. I prefer the second option, as you’ll usually get a much better price going straight to the source, even when paying for international shipping. One caveat though: do your best to ensure that your source sells genuine cells and not knock-offs. Do this by checking feedback and using a payment method that ensures you can get your money back if the product isn’t as described. For this reason, I like to buy my cells on Alibaba.com and AliExpress.com.

Charge voltage for li-ion cells is 4.2V per cell maximum. So for a 36V 10s battery you’d want to charge it to a maximum of 42V. Charging slightly lower will increase the life of the battery, but isn’t a requirement.

Hi I need help! I am building my own battery pack from old laptop batteries (18650’s). I bought the cheep $250 48v 1000w ebike conversion kit on ebay. I have many questions! It seems the perfect number of cells to connect in series are 13! This is a big problem for me because I am cheep and I already bought the Imax B6 battery balancer charger. I also bought 7x 6s balancer leads and 5x 4s leads. The Imax has a max charge voltage of 22.2v (so it sais in the manual), and a max balance of 6 cells at once. I also bought the parallel balance charging board. I don’t want to charge two or three packs at once to just have to turn around and charge one separately. So now I’m faced with the decision of making a 12 series battery or a 15 series battery (I will buy 5s leads in this case). The problem is with the 12 series battery the nominal voltage is only 43.2. Or a 15 series battery with a nominal voltage of 54. Which I’m pretty sure is a big no no because the controller is only meant to handle 48v within reason (13s max charge voltage of 53.3 and 12s 49.2 at 4.1 v per cell). But if I make it a 12s, running around most of the trip at 44v, will this drain the Amps faster because the motor wants 48v? I’m thinking no but just wanted some confirmation on that and if the controller can handle more volts. I could make a 15 series batter and just charge to 3.6 or 3.7 volts. Is this hard on the cells?

Before I seal my batteries in heat shrink, I like to wrap them in a thin layer of foam for added protection. This helps keep the ends of your cells from getting dinged if the battery receives any rough treatment, which can happen accidentally in the form of a dropped battery or ebike accident. The foam also helps to dampen the vibrations that the battery will experience on the bike.

Hey Brian, good question. You can actually do regenerative braking this way, the only problem is that you won’t be using the balancing circuit part of the BMS as it will charge straight back through the discharge circuit. Theoretically this is fine, with the exception of one specific case where this could be a problem. If you charged your battery at the top of a huge hill and then immediately rolled down that hill for a long time while using regenerative braking, you could actually overcharge the battery. That scenario is pretty rare though.

Should the voltage on the charger be exact, or can it be *higher* than my battery pack? For example, I need to charge a 19.2V pack. Does my charger have to *exactly match* (or come as close to as possible to) this 19.2V, or can I use a higher voltage charger, (say, 36V)? Will the charger automatically adjust to a lower voltage, allowing a 36V charger to charge my 19.2V pack?

Well, I’ve finally built a pack, which in the end turned out to be a 16s6p/7p made from recycled dead laptop batteries, charging to 67.2V and has a secondary offtake for a controller on the 13s positive (i.e. to route 16s to the FETs and 13s to the control circuit). Some of the groups were OK for 12Ah from 6 cells, others needed 7 cells; I just used what I had and as I got the laptop batteries for free, it was better for me spend the time testing them than to use 80 new cells, which would have been quite expensive.

Nickel Cadmium was the old standard for rechargeable consumer cells in the familiar AA, C, 9V series. They are known for robust characteristics, a good cycle life, and high discharge capabilities. They are still widely used in cordless power tools, R/C toys and similar applications that demand large currents, but for nearly everything else NiCad’s have been replaced by NiMH and Lithiums.

For this tutorial, I’ll be using the green Panasonic 18650PF cells shown above. Lately though I’ve been using 18650GA cells like these, which are a little bit more energy dense, meaning more battery in less space.

Now you’ve got all the info you should need to make your own electric bicycle lithium battery pack. You might still need a few tools, but at least you’ve got the knowledge. Remember to take it slow, plan everything out in advance and enjoy the project. And don’t forget your safety gear!

“electric bicycle battery case +electric bicycle battery case”

The Panasonic 18650pf is a good cell, that’s the one I used here. I also like the Samsung 26F, though it’s a fairly low power cell, and the Samsung 29E which is a bit higher power cell. The Samsung 30Q is a fairly new cell that has good specifications but doesn’t have as long a life – everything is a trade-off.

Maybe another way forward is to buy a pannier mounted supplementary battery pack (a proper one with a BMS) and to install it in parallel with the main one. The question then becomes whether to connect between the sprung terminals that go to the motor controller (which I believe to be the best thing to do) or into the little charging port jack. I presume that the charging port is connected to the charging side of the BMS and I don’t know how much current that port would take or whether it’s even a good plan to charge and discharge the main battery at the same time. I see significant potential for a high current through that small jack once I discharge via the main battery and a voltage difference exists between the supplementary batter and the main battery.

I’m sorry to hear about your bad experiences with AliExpress. I’ve done a lot of business there, and I’d say only around 5% of my transactions have been problematic. They have great buyer protection though and every time I’ve either gotten a full refund or had my product replaced at no cost. If you want a BMS from a source other than AliExpress or eBay, I recommend a company called BesTechPower. They make the highest quality BMS’s I’ve seen and they are the ones I use on my “top shelf” batteries. They are pricier, but you definitely get what you pay for. Just email their contact addresses and they can help you choose a BMS. http://www.bestechpower.com/

We like to use Anderson Powerpole connectors as the standard discharge plug on all of our ebike battery packs. These connectors are ingenious since they are genderless, allowing you to use the same plug both on both a load and a source, and the connector design allows them to withstand the arc of inrush current when plugged into capacitive loads much better than bullet style plugs. For the charging port, we like to use the female 3-pin XLR plug standard. This is directly compatible with the Satiator charger, and the quality Neutrik XLR plugs are rated for a full 15 amps per pin allowing very rapid charging. Unfortunately, this option is not available for the smaller Hailong frame batteries and we are forced to use the lower current DC 5.5mm barrel plug instead.

The single best manufacturer is BesTechPower, but their BMS’s are really expensive and they have a minimum order quantity of 2. For ‘best bang for your buck’ BMS’s I’d recommend Greentime BMS’s. They are great for most ebike applications outside of serious hotrods and speed machines. I use them on most of my packs.

As much as I want to build a pack just for fun and like buying tools like a spot welder I’m afraid of getting crappy cells at a high price. Whatj’s a good cell to charge at 1C for quick turn around and stay at a low price per cell? 36V 12A would be ok, more is a bonus.

Regarding the cell question, its a mixture of both. Cheap ebikes use cheap cells. You can bet the Sonders ebike had the cheapest cells available. Name brand ebikes usually use Samsung cells, but sometimes LG and occasionally Panasonic cells can be found in name brand ebikes (the Panasonics are some of the most expensive and so they are rarer). That being said, I’ve seen some shadier internet sites selling high quality (and genuine) Samsung/Panasonic packs, and I’ve seen some nice ebikes with some no-name cells. You should always check with the vendor/manufacturer if you want to ensure you’re getting good cells. Unfortunately, it can be hard to verify the cells yourself though without voiding the warranty, as they are usually sealed under shrink wrap. A good vendor will be happy to confirm the cells for you ahead of time and may even be able to show you some pictures of opened packs to verify.

Thanks! I’m putting together a new rig I need to tow a 50lb trailer over some soft sand…I’m realizing the proper system is paramount. Any recommendations for power/battery/controllers? DIY eBikes website?

12. Privacy Policy: Information submitted with an entry is subject to the Privacy Policy stated on the Electric Bike Technologies LLC Web Site. Read the Privacy Policy here: https://www.ebikekit.com/pages/privacy-policy.

It’s a good question. You need to use a 5s BMS. You can’t use a BMS rated for more cells because if the BMS see’s that cells are “missing” it will likely trip the protection circuit and your battery won’t provide any current. I’m not sure how easy a 5s BMS will be to find. A quick Aliexpress search shows me that something like this will probably work.

Safety disclaimer: Before we begin, it’s important to note that lithium batteries inherently contain a large amount of energy, and it is therefore crucial to handle them with the highest levels of caution. Building a DIY lithium battery requires a basic understanding of battery principles and should not be attempted by anyone lacking confidence in his or her electrical and technical skills. Please read this article in its entirety before attempting to build your own ebike battery. Always seek professional assistance if needed.

But there’s still another issue: now if I just slip my pack inside some shrink wrap tube, I’ll still have exposed ends. This is more or less ok structurally, though it won’t be very water resistant and it will look a bit less professional.

SLAs come in 6V or 12V increments, meaning you have to build your battery pack by combining these smaller SLAs in series and/or parallel to get the specific voltage and capacity you’re aiming for. This can be both an advantage and disadvantage; it gives you more room for customization but requires some work to combine the individual SLA batteries together into a larger pack.

This is also why the common and affordable RC smart-chargers are powered by a separate DC power supply. Many RC enthusiasts spend a day at a park, and while flying an RC plane, they have several other battery packs that are charging from their cars 12V system.

Do you by any chance have some spare parts you can swap in? A spare controller would you let you know if the controller is faulty and tripping early. Another battery would show you if the problem was battery related.

Then I took the sense wire labeled B1 and soldered it to the positive terminal of the first parallel group (which also happens to be the same as the negative terminal of the second parallel group, as they are connected together with nickel strip).

A big downside of lithium batteries is that they are much more expensive than lead acid batteries. Prices vary depending on the voltage and capacity of the lithium battery, but standard ebikes usually have lithium batteries starting in the $300 range and rising quickly from there. Most bikes I build have lithium batteries in the $400-$500 range.

The sense wires generally connect to the positive of each cell group, but sometimes there is one more sense wire than parallel groups because the first sense wire is intended to connect to the negative of the first cell group, then all the subsequent sense wires connect to the positive of each cell group. Each BMS should be labeled on the board to show where each sense wire goes (B1-, B1+, B2+, B3+, etc…)

Charge current depends on the cells. Most cells can take at least http://electricbikemotor.net some considerably more. It’s hard to know what cells you’re using. Assuming they are 18650pf Panasonic cells like I used here, 1A per cell would be fine, giving you a charge rate of 3A. They can actually take more than that, but there’s no reason to push them too hard if you don’t have to.

Thank you so much for taking the time to write the battery chemistry article. I am looking at buying my first electric bike, and needed to understand the differences in LiOn batteries. There are still retailers selling SLA battery pack bikes and wasn’t sure if that was what I wanted, or LiOn. Your article helped me greatly.

“diy lithium ion battery +replacement battery for electric scooter”

I should really change that $2 cutoff to more like $2.50, which is more reasonable for quality cells. Basically, the cheapest ‘good’ cells are Samsung 26F cells, which can be had for usually around $2.50 – $2.90 if you are buying in any large quantity, like at least 100. Expect to pay more like $3.00 or so if you’re batteries for a scooter only 40 cells. 26F cells are also limited to 5A discharge though, so you’ve got the same issue as with the NCR18650B cells from Panasonic.

the problem i have and the bit im confused on is this, i understand the negative on the entire pack goes to the negative on the BMS and the positive of each parallel cells goes to each sense wire but where are the charge and discharge wires going ? am i corrrect in saying that the positive of the pack goes to the charge and discharge socket on the BMS and that when the pack receives its charge it charges the pack and the discharge is when the pack is under load from the output of the pack i.e what ever its connected to for example your bikes motor? in your tutorial you havent shown how you connected the parallel groups of batteries together in series to give you the final pack voltage and capacitance but i’m assuming you linked them in series to get the toal 36v but on the pictures the first and last cells are split compared to the doubled up cells you have through out. am i also correct in saying that if you have 2 batteries connected together to form a cell then you dont need a sense wire on each battery because the two batteries are considered to be the same battery and when they charge and discharge they equalize as one shunts the other ? sorry for so many questions i have googled and googled and googled and as Einstein once said the definition of madness is doing the same thing over and over and expecting a different result, many thanks in advance .

Scooter / Light Bike. For Electric Bike Bicycle EBIKE (Conversion Type) amp Lithium Ion BATTERY. Bicycle Accessories. Case Material: ABS Aluminium alloy. Bike bag. Li-ion E-Bike Battery. Car & Truck P…

Maybe another way forward is to buy a pannier mounted supplementary battery pack (a proper one with a BMS) and to install it in parallel with the main one. The question then becomes whether to connect between the sprung terminals that go to the motor controller (which I believe to be the best thing to do) or into the little charging port jack. I presume that the charging port is connected to the charging side of the BMS and I don’t know how much current that port would take or whether it’s even a good plan to charge and discharge the main battery at the same time. I see significant potential for a high current through that small jack once I discharge via the main battery and a voltage difference exists between the supplementary batter and the main battery.

Now the game plan here is to weld parallel groups of 3 cells (or more or less for your pack depending on how much total capacity you want). To weld the cells in parallel, we’ll need to weld the tops and the bottoms of the cells together so all 3 cells share common positive and negative terminals.

There are two prevalent ideas in pack constructing in these modern days…one is to use larger pouch-like soft cells to construct the pack. The stealthiest battery chemistry by far is LiPo, large cells with power-dense cobalt in the anode chemistry, such as what comes in Hobby King cells. Here is what I mean by “large cell” LiPo. These are soft pouches and large. When you use a pack made of these it will consist of fewer wired together cells than if you use small cylinder cells.

Hey, I’m about to build my 16S2P pack from 32 Samsung INR18650-25R cells bought from batterybro.com. How far apart can their voltages be when you connect the parallel packs? They seem to all be charged between 3.52V and 3.56V.

You can certainly use a second 4.4AH battery in parallel to double your range, but you’ll want to make sure the batteries are at the same state of charge when you connect them in parallel, or use a diode in between them, to keep one battery from discharging the other if the charge states are unequal.

I also don’t have a spot welder, and for the purpose of building a single 16S2P pack, I’m not sure I want to splurge on that extra $100+. I do have a whole tub of flux and a temperature-controlled soldering iron, so I’ll be attempting to solder the cells instead (extra hot and fast with lots of flux to avoid conducting too much heat into the battery internals from dwell time).

You’ll see two dots where the weld was performed. Test the weld by pulling on the nickel strip (if it’s your first time using the welder). If it doesn’t come off with hand pressure, or requires a lot of strength, then it’s a good weld. If you can easily peel it off, turn the current up. If the surface looks burnt or is overly hot to the touch, turn the current down. It helps to have a spare cell or two for dialing in the power of your machine.

NiCd-Nickel Cadmium. This chemistry was half the size per a given power compared to SLA. But it has a low C-rate (Current producing capability) so anyone who made a pack out of them was restricted to low amps. There were no large packs for sale. E-bikers had to purchase rechargeable flashlight batteries and solder together a pack of a higher voltage, for which an off-the-shelf charger could be found to charge it up. Because of the low price of SLA chargers, 36V and 48V NiCd systems were common. When the price of nickel went up and the price of Lithium came down, NiCd died a quick death. Not even cordless drills use these anymore.

If you are using 2.5AH cells then yes, it will be 5AH with a 2p configuration. If you use cells with higher capacity, like Sanyo GA cells that are 3.5AH, then you’ll have a 7AH pack with only 2p. Make sure your cells can handle the current that your electric scooter (and namely the controller) will try to draw from it.

Believe it or not, most BMS’s can handle the current from regenerative braking in the discharge mosfets as its rarely more than 5-7A. Some BMS’s (called two wire BMS’s) actually use the same mosfets for charging and discharging. Those inherently should be more than capable of dealing with the load from regen.

Absolutely, a relay is the way to go. Use the keyswitch you bought to activate the relay, then the relay will carry the heavy current flowing through your battery’s positive discharge wire. Alternatively, you could install 9 or 10 of these switches in parallel. Just make sure you mark your keys accordingly 😉

When you buy a Hobby King pack, it will have a number of these large cell LiPo’s strung together like this 6 cell in-series (6S) pack. The big downsides of this pack is that it will only last you in best case maybe 300 charges and it is volatile, and susceptible to possible fire if not well managed and cared for.  When using cobalt-based LiPo, it is best to use some kind of BMS, and also you should charge it in a safe location.

Yea lead acid is a great way to cheaply get into ebikes and test new motor/controller combinations. Keep in mind though that your performance will increase when you switch to lithium. It’s easy to do though, as the bike doesn’t care what chemistry it receives, it just sees volts and amps. Good luck!

Regarding you question, if I understand you correctly, it seems that your 18650 lithium battery will be smaller than the old NiCad battery, so you have extra room in the battery box that needs to be filled, correct? My recommendation is to use some type of fairly rigid foam to fill the space. It adds almost no weight and it also helps cushion the battery pack.

This pattern continues until we’ve got all 10 parallel groups connected. In my case, you can see that the first and last parallel groups aren’t welded on the top side of the pack. That is because they are the “ends” of the pack, or the main positive and negative terminals of the entire 36V pack.

Also I wanted to “hide” the batteries in the Brompton frame aligning the batteries in file, I understand it would not have a long range but would be quite stealthy. If you have any recommendations please do tell me

Spot welders for batteries aren’t the same as most home spot welders. Unlike the large jaw spot welders for home workshops, battery spot welders have the electrodes on the same side. I’ve never seen them for sale in the US, but they can be found pretty easily on eBay and other international commerce websites. My full time use welder is a fairly simple model that I got here. A highly recommended source for a slightly nicer spot welder design (pictured below) with both mounted and handheld electrodes can be found here.

Now I’ve got all of my pack sealed in heat shrink with my wires exiting the seam between the two layers of shrink wrap. I could have stopped here, but I didn’t particularly like the way the shrink fell on the wire exit there, from a purely aesthetic standpoint. So I actually took a third piece of shrink wrap, the same size (285 mm) as that first piece and went around the long axis of the pack one more time to pull the wires down tight to the end of the pack.

“36v scooter battery -battery scooters”

Hailong makes some of the more refined of the generic battery enclosures from china. You’ll see them online everywhere, stuffed with whatever cells and BMS circuit appropriate to the market being addressed. They secure to the water bottle eyelets on the down tube of your bike frame, and the narrow height of this pack design allows it to fit even on smaller or hybrid frame geometries that wouldn’t normally fit a pack. We have the smaller Hailong-01 enclosure in 36V (10s 5p) and 52V (14s 4p) layouts suitable for 20-25A current setups, and the larger Hailong-03 enclsoure in 36V 23.5Ah (10s 7p) and 52V 16.5Ah(14s 5p) sizes for higher current and capacity. 

LiFePO4 is currently widely available for purchase as e-bike packs complete with BMS on ebay and other online merchants. Mostly it is sold by small companies. Also, most of the commercially available e-bikes powered by lithium batteries are using the LiFePO4 chemistry.

I say this because I am assuming that the wire from the motor that connects to the battery and receives power from the battery would be the same wire that provides power in reverse to the battery when regenerative breaking. With this particular BMS, would it require a different wire to do the regenerative braking?

Now you have the required specs on the pack, namely its voltage and capacity, so it’s a matter of finding one that meets your budget and weight restrictions. To a first order, for a given voltage and capacity, NiCad will cost twice as much as lead acid but come in at half the weight, NiMH will be 30% lighter and more expensive than NiCad, and lithium will be twice the cost of NiMH and a further half the weight again.

I have an old 12V DC Brush Motor which its consumption is around the 12A, 13 A and I built a Battery pack, with two groups of batteries, (4S6P)+(4S6P), which makes a total pack with 14,8V 30A. To make this battery pack I used 18650 Samsung Cells 2600 mAh.

HERE ARE 99 GENIUNE LG LGABB41865 18650 2600MAH CELLS. THEY ARE IN MODEM BATTERIES, JUST NEED A FLAT SCREW DRIVER AND PRY THE CASE AT THE SEAM. THEY ARE IN 12V (3S1P) SET UP ALREADY SO YOU CAN SAVE A …

Interesting that they claim the controller is balancing the two batteries. I highly suspect that is false, and just marketing fluff, but who knows. They probably have a simple diode built into the internal battery. I checked with a friend and he reminded me that it would be a good idea to include a diode in the discharge cable of your auxiliary battery. That way if you ever plugged in your auxiliary battery when it was low on charge and the bike was fully charged, the bike wouldn’t try to charge your auxiliary battery in reverse.

Wow, that’s a really interesting way to do it. So their auxiliary battery connects to the charge port of the primary battery, which means it’s not actually powering the bike but rather just charging the primary battery, which then powers the bike. Not the most efficient way to do it, but it’s simple and elegant.

Continue down the row of cells placing a weld on each cell. Then go back and do another set of welds on each cell. I like to do 2-3 welds (4-6 weld points) per cell. Any less and the weld isn’t as secure; any more and you’re just unnecessarily heating the cell. More and more welds won’t increase the current carrying ability of the nickel strip very much. The actual weld point isn’t the only place where current flows from the cell to the strip. A flat piece of nickel will be touching the whole surface of the cell cap, not just at the points of the weld. So 6 weld points is plenty to ensure good contact and connection.

100~240VAC Universal AC input Full range LiFePO4/Lithium Ion/Lead Acid 4000W Battery Charger Two S2500 model in parallel. Power:4000Watts; Protection function: / Overload / Over voltage / Over temperature / Over current / Reverse polarity / Power off or trickle after finished charging; 2 years warranty

The best method is batteries for electric scooters canada use a trusted vendor. They interact with the cell providers and are the best way to confirm whether cells are fake or not. It can be incredibly difficult to tell whether a cell is fake or not just by picking it up from the table. There are some giveaways like different printing on the wrapper, slightly different color, different stamp, different weight or different shell design, but all of those can be mimicked. That’s why I use only a handful of vendors that I’ve worked with continuously and who I know have always given me good quality cells. I had to go through some low quality ones until I found the sources I buy from now.

NiCd-Nickel Cadmium. This chemistry was half the size per a given power compared to SLA. But it has a low C-rate (Current producing capability) so anyone who made a pack out of them was restricted to low amps. There were no large packs for sale. E-bikers had to purchase rechargeable flashlight batteries and solder together a pack of a higher voltage, for which an off-the-shelf charger could be found to charge it up. Because of the low price of SLA chargers, 36V and 48V NiCd systems were common. When the price of nickel went up and the price of Lithium came down, NiCd died a quick death. Not even cordless drills use these anymore.

If any one battery cell varies significantly from the others, do NOT connect it to the other cells. Paralleling two or more cells of different voltages will cause an instantaneous and massive current flow in the direction of the lower voltage cell(s). This can damage the cells and even result in fire on rare occasions. Either individually charge or discharge the cell to match the others, or more likely, just don’t use it in your pack at all. The reason for the voltage difference could have something to do with an issue in the cell, and you don’t want a bad cell in your pack.

I am just trying to install a battery on a velomini 1 that I traded for. I don’t have a problem using the above battery as a hang on battery, but don’t know if it has the BMS in it or if my current charger would charge it. It is pretty cheap.

I’m sorry to hear about your bad experiences with AliExpress. I’ve done a lot of business there, and I’d say only around 5% of my transactions have been problematic. They have great buyer protection though and every time I’ve either gotten a full refund or had my product replaced at no cost. If you want a BMS from a source other than AliExpress or eBay, I recommend a company called BesTechPower. They make the highest quality BMS’s I’ve seen and they are the ones I use on my “top shelf” batteries. They are pricier, but you definitely get what you pay for. Just email their contact addresses and they can help you choose a BMS. http://www.bestechpower.com/

I haven’t seen that exact BMS in the flesh before, so I can’t speak too confidently about it. The description claims it has a balancing feature and so I assume it does, but I’ve also seen BMS that were supposed to have balancing capabilities, but arrived with the balancing components missing from the board.

Typically you can expect somewhere between 25 and 70 miles of travel on a single charge of an ebike. If you’re riding hard on full power expect less; manage your battery life well and you could get more.

Select items that are not included in ShippingPass will ship for free but with value shipping. Look for items sold by Walmart.com and marked with FREE shipping. You will also see this noted in checkout.

Lastly, there’s a small chance that it’s just a faulty BMS. This method is annoying, but if all else fails then you can try swapping out the BMS. More than likely though, the BMS is doing it’s job because one of the cutoff conditions is fulfilled and it’s just trying to protect the pack.

There are formulas out there for calculating the exact size of heat shrink you need but I often find them overly complicated. Here’s how I figure out what size I need: take the height and width of the pack and add them together, and remember that number. The size of heat shrink you need when measured by the flat width (half the circumference) is between that number you found and twice that number (or ideally between slightly more than that number to slightly less than twice that number).

When it comes to nickel strip, I also like to use Aliexpress. You can also find it on ebay or even a local source if you’re lucky. Once I started building lots of batteries I began buying pure nickel strip by the kilogram here, but in the beginning I recommend you pick up a smaller amount. You can get pure nickel strip for a good price in smaller amounts from a seller like this one, but you’ll still get the best price by buying it in kilo or half kilo quanitites.

Most lithium batteries that are designed to mount to ebikes also come with some form of locking system. These have varying degrees of effectiveness. The type with a little pin that slides into a thin sheet of steel are the easiest to steal by mangling the thin steel locking plate. Just take a look at your battery and ask yourself “how easily could I steal this battery if I had some basic hand tools and a 60 second window of opportunity?”

40% grade hills? That’s huge! You’ll definitely want a cell that can perform at high current since you’ll be pulling peak power from those cells to get up those big hills. Something like the Samsung 25R would be a good choice for this application.

Choose an electric bike from top brands like Razor, Monster Moto and Jetson, and your child will be burning rubber in no time! In sporty colors like yellow, green and red, your little rider can cruise in style at speeds of up to 15 mph. Adventures can usually last up to 40 minutes, or 10 miles, on a single battery charge. To ensure you get the right bike for your child, carefully examine the age and weight restrictions of your new electric bike.

A High-performance Motor acheives a top speed of 20-30km/h with a range of 20km means your ebike commute just got easier. Folding style, portable convenient, easy storage. You can lock your bike by ap…

And if you don’t want to purchase my book (or you already have a lot of ebike knowledge), you can still support this site by simply clicking on this link before you shop on Aliexpress. Basically, that’s an affiliate link that shows Aliexpress that you came to them via my site. It doesn’t effect you at all, but if you make a purchase, this site will get a small percentage of the profit that Aliexpress makes. It’s a simple way to help support this site so I can pay the hosting and keep providing more free info (and to keep this site free of annoying ads). I have some of those affiliate links on a limited number of articles on my site. When I personally buy and test products that I find to be a combination of great quality and great prices, like these batteries, for example, I like to share them through those affiliate links. Again, it costs you nothing, but it allows me to keep cranking out more info and content for you guys!

This is what I refer to “small cells”, the 18650 (cordless tool) type cells which need to be spot-welded or soldered together to form a large pack. The big advantage of these cells is they offer better cooling because of the nature of their shape to the LiPo soft pouches, and therefore have the capacity to last longer.

For example, suppose you see a 24V 4Ah NiMH battery pack on ebay, that is rated for 1C continuous and 2C max for short times. You might want to get two of these to make a 48V 4Ah battery for your ebike. You calculate that the range will be more than adequate for your short commute to work and back. The problem is that 1C is just 4 amps, while your ebike will probably draw 10-20 amps. If these cells are subject to such discharge rates, then the voltage will sag considerably, leading to slower performance, and the cycle life of the packs will be greatly reduced.

For a complete write up on LiFePO4 care and trouble shooting read our story here. LiFePO4 cells nominal voltage is generally from 3.0-to 3.2 volts, and generally, lifepo4 is a heavier and less power dense than available LiPo batteries and is not capable of as high of amperage discharge.