“electric bike motors and batteries _ebike battery”

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.

2. Lithium-Ion Shrink Wrapped Shrink Wrapped Lithium-Ion Batteries are housed in a soft PVC heatshrink material. It protects the battery from moisture and short-circuits, but not from being dropped or punctured. View Shrink Wrapped Lithium E-Bike Batteries

Finally found it. WOW!! Exactly what was needed. I struggle with conceptualizing verbal descriptions. You solved that! With the new JP Welder from Croatia my first welded build will soon be a reality. Thanks for all you do for eBiking!

That’s a tough one to answer. It depends on the power of the battery (typically 24, 36 or 48V), the power of the bike (limited in the UK to 250W), the bike’s battery management system, and the way you ride. Some bikes allow you to choose different levels of assist to prioritise speed or battery life, which makes predictions of battery life even more difficult.

3. Lastly, I assume if the BMS & battery were able to produce the 50A X 24V watts of 1200W that my electric motor would only ever use the 500W it is rated for? As in the E bikes controller would only draw around 500W?

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.

I was wondering, though, if I could use thick gauge wire instead of nickel strips (copper wires are much more accessible). Would there be any downsides to that, given that I’m going to be using solder anyway?

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.

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.

Lithium Polymer is by far the lightest battery option out there. LiPoly cells that can handle very high discharge currents are becoming widely available and are especially popular in the R/C crowd for electric airplanes and helicopters, but ebike LiPoly packs are often made with cells that are only rated to 1C or 2C, and these don’t usually deliver a very good cycle life count. The cells are produced in a thin plastic pouch rather than a metal can, making them structurally quite vulnerable unless supplied with a rigid enclosure. Although Lithium Polymer has a reputation for being volatile and failing with spectacular pyrotechnics, there are companies making cells these days that are quite stable and can pass the fullUN 38.3 overcharging and puncture tests without any flames.

Short for bicycle motocross, BMX is a type of bike designed for dirt, street, flatland, and park rides. This is a more casual form of cycling, which riders enjoy for both pleasure and sport. BMX riding…

Rated Capacity: 10Ah. Recommended to be used with 36V 250W electric bicycle motor. 36V 750W 20″ Front Tire e-Bike. Charge Current: 2A. Model: Bottle Type. 1 Year manufacturer warranty for CHARGER. Use…

The higher C-rate of 3C for the newer LiFePO4 (from A123) keeps these popular so you don’t need a huge pack to get fairly adequate amps. To get a continuous 24A, you’d only need a 8-Ah battery. Fairly affordable, and small enough to fit in a bike frame.

When it comes to buying your cells, you might be able to find a local source, or you can order them straight from 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.

Edit: if this article was helpful, you may like our newer article on the latest NCM/NCA battery chemistries, and also our article on high-performance batteries that are NOT made from LiPo. If you have narrowed your battery choice down to LiFePO4, make sure to check out Dogmans expert guide to LiFePO4 batteries.

This is a very simple layout where each column of 3 cells is connected in parallel and then the 10 columns are connected across in series from left to right. The BMS board is shown at the far right end of the pack. You’ll see how the pack represented in the drawing will come together in real life shortly.

From what I can tell, the Faraday Porteur uses a 36V 5.8AH battery made from the same cells I used on the battery in this article. They only have two cells in parallel though, not three like in my battery shown here. You can build a battery just like theirs, or a 36V battery of any capacity. You could make a 12AH battery and triple your total range! Heck, you could even take a premade battery like this one and just replace the discharge cable with a XLR connector – it’d be an auxillary battery over three times as large as theirs for 2/3 the price!

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 1000 charges.

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. 

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.

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. 

Sure, it is possible to solder directly to the cells (though it can be tricky without the right tools). The problem with soldering is that you add a lot of heat to the cell and it doesn’t dissipate very quickly. This speeds up a chemical reaction in the cell which robs the cell of its performance. The result is a cell that delivers less capacity and dies an earlier life.

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.

In 2012, the future of LiPo in e-bikes looks bright. Most large EV manufacturers are focusing on LiPo as the lithium battery power of the future. LiPo technology is developing fast and becoming safer, more reliable, cheaper, and with a higher life expectancy. Since LiPo cells are being developed to be safer, more efficient and more economical (mostly for main stream products such as the automobile) the electric bicycle industry will be able to piggy-back and utilize the newly available technology at an affordable price. Currently, the latest “best” chemistry involves Manganese-Cobalt which is a lot more stable than the cobalt chemistry of the past.

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 eZee flat packs are one of the nicer rear rack battery options that we’ve dealt with, featuring a locking on/off key switch, and a rail system to slide into the eZee double-decker rack or attach with our more universal CNC battery anchors. They hold up to 70 cells, allowing for both a 36V 19Ah (10s 7p) and 48V 14Ah (13s 5p) options. The 36V pack has UN38.3 certification for air shipping, and can handle up to 40A motor controllers fine, while the 48V pack shouldn’t be used above 25A.

Sorry Benoit, but that won’t work. The BMS will expect the full 10 cells and when it sees that cells are missing, it will assume they are at 0V and not provide any power. You need a 7s BMS, which are pretty commong. 8s will be harder to find for li-ion, but you could do 8s with LiFePO4 and those 8s BMS’s are common.

13. Winners will be emailed directly by the marketing manager. Must respond within a week. Winner may also be announced on Facebook.               14. Sponsor: The Sponsor of the Sweepstakes is Electric Bike Technologies LLC, 951 River Road, Croydon, PA, United States;

I wouldn’t say incompatible but us 220 uses the full phase peak to peak of both legs of the elec drop. European and others uses a half phase (I believe) where zero to peak is 220v. Have you had a chance to look into this for me as my welder and box of new 18650’s are sitting idle waiting for me to start welding. Thanks

Why do we alternate sides of the pack during the welding process? We do it because in this way we connect the positive terminal of each parallel group to the negative terminal of the next group in line. That’s how series connections work: always positive to negative to positive to negative, alternating between the two.

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 batteries electrical doesn’t have as long a life – everything is a trade-off.

Some of the NMC sellers are advertising their chemistry as 5C, but real-world use by E-bike builders has them calling NMC a solid reliable 3C chemistry, which can provide a continuous 30A from an affordable and compact 10-Ah battery (temporary peak amp-draws can be higher, as it is with any of these chemistries). This may sound only as good as the most recent LiFePO4, but NMC is smaller, and is not as fussy about keeping the individual cells balanced.

Almost all consumer electronics that have a plug-in charger these days are powered with lithium batteries because they can store about 3 times more energy than NiMH. Small devices like cell phones, mp3 players, and other gadgets typically have lithium-polymer packs, as these can be formed in conveniently shaped thin rectangular pouches. Larger devices like laptops and the new lithium cordless power tools generally use cylindrical Lithium-ion cells of a size smaller than a ‘C’ but bigger than a ‘AA’. These are spot welded in series/parallel combination to give an appropriate voltage and capacity for the job.

“bike batteries +”

Furthermore, if you have more capacity than required, then you also have the opportunity to do partial charging of the battery with a Satiator or similar device, so that instead of charging the pack to 100% to squeeze out every km, your standard charge is set to a lower 80 or 90% level. This can have a pronounced effect increasing  both the cycle life and calendar life of a lithium battery by several fold. 

My daily driver ebike has 8 cells paralled (14s8p) and it’s been working great for a long time. You can certainly make two 13s4p packs and parallel them after the fact, but don’t be afraid of making a single pack. As long as you use good quality cells, the risk of a parallel group dying is incredibly small.

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.

Connections are made with solid Nickel strips, spot welder to each cell. Each cell and each series is tested before assembly. The BMS will prevent over charging and will balance the cells after a full…

An older battery technology that was popular around 10 years ago as replacment for lead acid in some more expensive commercially available e-bikes. Today it has been obsoleted  in e-bike applications because of the recent availability of LiPo and LiFePO4 cells. NiMH is a finicky technology to deal with. The packs do not have long life expectancy, and have to be treated delicately. One big batteries for electric scooters canada for DIYers is that its very hard to safely charge NiMh cells that have been soldered together in parallel. Extra care is needed for NiMH in both assembling and charging.

Regarding the soldering of cells: generally it is not recommended as no matter how you do it, a soldering iron will still transfer more heat than a spot welder. That being said, I have seen packs that have been welded using both solid or braided copper wire. I’ve also seen someone use copper wick soldered to the cells terminals. It’s impossible to know exactly how much of an effect that the heat transfer had on the cells but if you don’t mind taking a risk of some level of deterioration of the cells performance, then it technically is possible to solder the cells together.

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... 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: 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. This is our smallest battery offering specifically aimed at people who have to travel or fly with their ebike. Each module is 36V 2.7Ah, so just under 100 watt-hours, exempting it from most of the heavy shipping restrictions. You can parallel connect them for as much capacity as required, and series connect them for 72V setups. Designed and made in Canada by Grin Tech, full details here. Power ratings of E-bike kits and the C-rates of batteries for sale are ALL highly suspect. The endless-sphere authority on batteries and their C-rates is Doctor Bass. He has nothing to gain from misrepresenting any chemistry or battery manufacturer. I must admit I am annoyed if a new battery is claimed to be a 5C chemistry, but testing shows it to survive better at 3C, however…a misrepresented battery that is a true 3C is still a good thing. NCA…LiNiCoAl / Lithium Nickel Cobalt Aluminum (sometimes called NCR) The battery chemistry research industry is still driven by the HUGE global sales of laptop computers, cellphones, and cordless tools. Mass production has made the 18650 format the best cost per volume cell. The 18650 number means that it is 18mm in diameter, 65mm long, and the zero means it is a cylinder instead of a flat foil packet. (the 18650 is roughly the size of an adult male thumb) [edit: in 2014, Tesla electric cars are now using Panasonic NCA batteries] 3. Yes, 18650’s with capacity ratings of 6000 or 8000 mAh are fake. The technology simply doesn’t exist to put that much energy in a cell that size on an economical level. In a few years we might be there, but not right now. Currently, the biggest cells are in the high 3,000 mAh range for 18650’s. 26650’s are larger cells and so those can have higher capacities, but there are many fewer options and variety of 26650 cells, so 18650’s are the common cells used in ebike packs. 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. 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 If you want to step up a notch on the quality ladder, here is another good charger that I prefer even more, though it’s a bit more expensive: http://www.aliexpress.com/store/product/aluminum-shell-36V-42V-2Amper-Li-ion-Lipo-battery-charger-high-quality-charger-for-10S-li/1680408_32275847257.html Here at Grin we've been dealing with ebike batteries for a very long time during which we've offered over 100 variants of NiCad, NiMH, LiFePO4, LiPo, and Lithium-Ion packs in all kinds of voltages, geometries, and capacities. It's been a love/hate relationship over those years, but the more recent mass production of 18650 lithium cells for high power consumer goods like power tools has shifted things to the love side, with ebike batteries that are cheaper, lighter, and with far longer life span than we could have ever wished for in the past. We're happy to stock both frame mount and rear rack mounted batteries from 98 watt-hours to 1100 watt-hours in size to suite the needs of most electric bicycle conversions.  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…) 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. The ShippingPass assortment is continually being optimized. Products are added and removed for lots of reasons, but the main reason is to show items that we're 100% sure we can deliver within the promised timeline. 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. 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... [redirect url='http://bestelectricbikebattery.com//bump' sec='7']

“battery for electric scooter +48 volt battery for electric scooter”

Is there same officially recognized method to come up with C ratings? Ping claims 2C on his LiFePo4 batteries, my Chinese-made “BMC” battery claims 3C. Can they just sort of say whatever they want? How do we determine the “real” C rating?

As a side-note, the Boeing 777 Dreamliner battery fire was using LiCo. They wanted a battery that was as light as possible, and as compact as possible. I am not an engineer, but I agree with the statement made by “Tesla” electric car maker Elon Musk, when he said that there was NOT adequate heat insulation between each cell. Better individual cell insulation would prevent a bad cell that was getting hot from heating up the surrounding cells. That is what led to a domino effect. The Tesla cars have a cell cooling system, and the on-board computer can detect and cut-off any cell-group that is getting hot.

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?

“…The wax is micro-encapsulated within the graphite matrix. When the wax melts, there’s enough surface tension between the wax and a graphite matrix that it doesn’t leak out. You could heat the material up to 300° C (570F), and it will become soft enough for a thumbprint, but it will remain solid…”

C values seem to be as much about cell packaging as chemistry for LiFePo/LiMn/LiNiCoMn Pouch and prismatic cells with high AHr per cell tend to have a C value of about 1 to 1.5. So cheap packs both cased and shrink wrapped or from suppliers like Ping seem to be like this. Cylindrical cells from A123 or Headway tend to have C values of 3C to 5C upwards. And for a fully built pack, C is as much about cells in parallel as anything. eg 10s2p having twice the C of 10s1p Again BMSBattery/GreenBikeKit are now selling LiFePo Headway based packs with a BMS and with C values of 3C to 5C and either cased or shrinkwrap.

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.

But having read through the document mostly, not completely, I simply stopped reading further due to incorrect usage of words and many bad spellings, some of which would not be caught by a spell checker – “table” for “stable” for example.

The best method is to 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.

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.

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.

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 http://usebikeparts.com 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.

Once I’ve got all the cells I need checked out and ensured they have matching voltages, I like to arrange them on my work surface in the orientation of the intended pack. This gives me one final check to make sure the orientation will work as planned, and a chance to see the real-life size of the pack, minus a little bit of padding and heat shrink wrap.

Now take your trip distance, multiply it by the appropriate watt-hours/km from the table above, and you’ll get the total minimum watt-hours required for the trip. Take the watt-hours you’ve estimated and divide it by the voltage, and you now have an estimate on the minimum amp-hours you’ll need from the pack.

Capacity: 30Ah. output: 71.4V 5A. Lifecycle of single cell: >85% capacity after 700 cycles, > 70% capacity after 800 cycles. (<1C discharge rate and <1C charge rate). Lifecycle: > 85% capacity after 5…

It is possible to do it that way, however there are some compelling reasons not to. 1) By first joining all the series cells you would end up with multiple high voltage groups, which means both the chance and consequences of an accident are greater. When you’re working with lots of exposed batteries with nickel conductors and metal tools flying around, the last thing you want is more high voltage possibilities for shorts. 2) Doing series cells first would be come unwieldy, physically. A series group is only connected at either the top or bottom of alternating cells. Without having multiple cells side by side to add stability, a long chain of single cells will need either a pile of glue or some type of physical holder to support the chain. and 3) most battery spot welders can only reach about 2 cells deep into a pack, meaning you’d have to either add very short nickel strips to each series group connecting only two groups (which means twice the welding and twice the cell damaging heat) or have long uncontrolled nickel strips hanging off the sides, again risking shorting.

“battery bike _diy electric bicycle”

and i also have another question if i charge the 2 packs seperately then connect them to my bike in parallel do they both have to have the same capacity and the same wear for instance i currently have 2 sets of batteries (sla’s) one of which is an old set at half original capacity or there abouts and the new ones hold the full charge so can they be connected together to give me 1 1/2 x my range? or if im going to put a double pack on do i have to use and charge them together so theyre all at the same state of charge and http://usebikeparts.com the same as ideally i would like to only have to carry a second pack when i require the extra range.

Nickel Metal Hydride batteries are about 20% lighter and 30% less voluminous than a NiCd pack of the same capacity. They have similar discharge and charge characteristics, but because of the higher energy density they are available in higher capacities than NiCd packs. Because NiMH is safe for disposal in the landfill while Nickle Cadmium is not, the metal hydride has almost completely replaced cadmium in most consumer batteries.

3. Yes, 18650’s with capacity ratings of 6000 or 8000 mAh are fake. The technology simply doesn’t exist to put that much energy in a cell that size on an economical level. In a few years we might be there, but not right now. Currently, the biggest cells are in the high 3,000 mAh range for 18650’s. 26650’s are larger cells and so those can have higher capacities, but there are many fewer options and variety of 26650 cells, so 18650’s are the common cells used in ebike packs.

LiPo packs that are homebuilt (without a BMS) can be extremely dangerous if you do not approach your battery with a lot of knowledge and care. Be sure to research extensively before building such a pack. Many E-bikers construct packs with no BMS using Turnigy/Zippy packs, acquired cheaply online through the Hobby King company which is based in China.  For those who risk running their batteries without BMS they still use sophisticated chargers to balance their packs and constantly monitor the health of their cells.

If the 4P10S multi-tube arrangement was for occasional use on long journeys, then it would be reasonable to release all of the cells and to charge them individually or in parallel to about 4V using a normal little single cell charger. Each would then be “top balanced” yes? Then mount them in the tubes, compress and connect the top terminal array and good to go. I’ve still got the quandary about whether to connect them in parallel to the main battery large output terminal.

If you are excited about this improvement in battery chemistry, (NCM being 25% smaller/lighter that the fussy LiFePO4, and 300% better C-rate than the reliable and non-fussy LiMnO2) you may also be asking the question…What chemistry is next?

For a heavy trailer, I’d add a second brushed motor to the cart, whether the bike has a motor or not. You’d only need 24V, and here’s a discussion about powered trailers. The most important thing for going over sand is to have the fattest tires you can fit onto the trailer.

Another excellent answer, thanks so much! Now it has arisen a few related questions, if you don’t mind answering them. I’m using authentic Samsung ICR18650-26FM cells. I had already purchased a 24V 15A BMS before I slightly understood all of this. I was also able to obtain more cells since my original idea, so I was planning a 7S10P pack (around 30Ah), 70 cells total. I see each cell can do around 5A, making a 10P pack put out 50A total. If I stick with my 24V 15A BMS, that will give me 15A * 24V watts, or 360 watts total for my 500 watt motor. I’m going to number these to make it easier:

This is our smallest battery offering specifically aimed at people who have to travel or fly with their ebike. Each module is 36V 2.7Ah, so just under 100 watt-hours, exempting it from most of the heavy shipping restrictions. You can parallel connect them for as much capacity as required, and series connect them for 72V setups. Designed and made in Canada by Grin Tech, full details here.

I didn’t include a charging a section in this article, as this was just about how to build a lithium battery. But here’s a video I made showing you how to choose the appropriate charger for your lithium battery.

Regarding that welder, I’ve used it on a 20A circuit but I don’t own it (it belongs to a friend of mine) so I can’t give you the best firsthand experience as I’ve only used it at his place on a 20A circuit. My welders, which are similar but a slightly earlier model, are run on a 20A circuit at my home. I live in Israel and we have 220V wiring at home like in Europe, so I can’t tell you for sure how it will work on 110V. If there is the option of running it off 220V in your garage or laundry room, that could be another option, but I’ve heard of people running on 110V in the US without problems so I can’t say for sure. Sorry I’m not more help on that front.

One of the main disadvantages of lead acid batteries is their weight. There’s no beating around the bush here, SLAs are HEAVY, as you might guess by the inclusion of “lead” in the name. You’ll need a strong mounting solution on your ebike to handle the extra weight of SLAs. You should also be aware that lugging that extra weight around is going to negatively impact your range. The best way to improve the range of any electric vehicle is to reduce weight, and SLAs are kind of going the opposite way in that regard.

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.

I buy that pink cells, Samsung ICR18650-26F. The cells have 3,9V, is a little too, only one with 3,82 and the other 3,87. I want to do a pack with 4parallel and 7serie (28 cells), it is acceptable conect them? Any sugestion is welcome.

The figure that matters most when comparing how far a given battery pack will take you is not the amp-hour capacity but the total energy stored watt-hours. To make things more familiar, one watt-hour is one-thousandth of a kWh, the unit of energy used to measure household electrical usage. The watt-hours stored in a battery pack is approximated by taking the actual amp-hours and multiplying it by the pack voltage.

I want to take the apart and use the cells to make a 48V 16.8ah battery. Would you advice against this? Would 48V provide a noticeable difference in the power of my motor? (It is a 500W Falco Direct Drive Hub Motor)

The eZee flat packs are one of the nicer rear rack battery options that we’ve dealt with, featuring a locking on/off key switch, and a rail system to slide into the eZee double-decker rack or attach with our more universal CNC battery anchors. They hold up to 70 cells, allowing for both a 36V 19Ah (10s 7p) and 48V 14Ah (13s 5p) options. The 36V pack has UN38.3 certification for air shipping, and can handle up to 40A motor controllers fine, while the 48V pack shouldn’t be used above 25A.

Manufacturers usually rate their cells’ capacity at very low discharge rates, sometimes just 0.1c, where the cells perform at their maximum. So don’t be surprised if you’re only getting 95% or so of the advertised capacity of your cells during real world discharges. That’s to be expected. Also, your capacity is likely to go up a bit after the first few charge and discharge cycles as the cells get broken in and balance to one another.

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…

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 am planning on making a 6S2P LifePO4 pack that has a voltage of 19.2V. I have a 6 cell BMS that does balancing (and that is intended to work with 6 LifePO4 cells). I need some help selecting a charger to charge this pack, however, particularly regarding the charger’s voltage specification.

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.

One more thing to note about large diameter heat shrink: unless otherwise stated, this stuff usually shrinks about 10% in the long direction, so you’ll want to add a bit extra to the length to account for both overlap and longitudinal shrinkage.

The higher C-rate of 3C for the newer LiFePO4 (from A123) keeps these popular so you don’t need a huge pack to get fairly adequate amps. To get a continuous 24A, you’d only need a 8-Ah battery. Fairly affordable, and small enough to fit in a bike frame.

Hi, if this is the first time you’ve heard about us, we recommend that you search “bmsbattery” or “bms battery” on Google or any other search engine to find out more about our excellent products, service and good reputation.  Time has proven that we are the best

We also maintain stock of replacement vertical seattube batteries that have been in use in the eZee bicycle line since time immemorial. If you have an eZee bike circa 2008-2012 with the Phylion lithium battery pack, you’ll be in for a serious upgrade with over twice the capacity in the same size and weight.

your post have been extremely infomative, i am trying to DIY a pack for my electric scooter for a 36V and around 5AH pack should it be 10S 2P? sorry if i am not clear, kinda a beginner myself. and BMS wise what kind should i use?

The battery cells have now been assembled into a larger 36V pack, but I still have to add a BMS to control the charging and discharging of the pack. The BMS monitors all of the parallel groups in the pack to safely cut off power at the end of charging, balance all the cells identically and keep the pack from being over-discharged.

“scooter battery -lithium battery electric bike”

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.

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.

So let say main point to count the power is to count the power is to know what type of the controller i have (i have check my batt connection goes to PCB which has sensors it self and whole unicycle controller… ) how to know ? Or in primitive way i can count like my batt is 20A and 36W so max power can be 720W but its peak on continues?

I’m sorry but I’m not certain. Here in Israel we are on 50hz so I haven’t tried that model on 60hz. I do however have some friends in the US that have that model on 60hz. They have been happy with it, but I haven’t used it myself so I can’t say how it compares to my experience.

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.

NCA…LiNiCoAl / Lithium Nickel Cobalt Aluminum (sometimes called NCR) The battery chemistry research industry is still driven by the HUGE global sales of laptop computers, cellphones, and cordless tools. Mass production has made the 18650 format the best cost per volume cell. The 18650 number means that it is 18mm in diameter, 65mm long, and the zero means it is a cylinder instead of a flat foil packet. (the 18650 is roughly the size of an adult male thumb) [edit: in 2014, Tesla electric cars are now using Panasonic NCA batteries]

A quick note: when you get into large sizes of heat shrink, the method of quoting the size often changes from referring to the diameter of the tube to referring to the flat width (or half the circumference when in a circle). This is because at these large sizes, it’s not so much a tube anymore as two flat sheets fused batteries for e bike sort of like an envelope. Keep that in mind and know what size is being quoted when you buy your large diameter heat shrink tube.

3. Lastly, I assume if the BMS & battery were able to produce the 50A X 24V watts of 1200W that my electric motor would only ever use the 500W it is rated for? As in the E bikes controller would only draw around 500W?

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!

The BMS I chose is a 30A maximum constant discharge BMS, which is more than I’ll need. It’s good to be conservative and over-spec your BMS if possible, so you aren’t running it near its limit. My BMS also has a balance feature that keeps all of my cells balanced on every charge. Not all BMS’s do this, though most do. Be wary of extremely cheap BMS’s because that’s when you’re likely to encounter a non-balancing BMS.

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

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…

“electric scooter battery -e bike battery”

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.

My daily driver ebike has 8 cells paralled (14s8p) and it’s been working great for a long time. You can certainly make two 13s4p packs and parallel them after the fact, but don’t be afraid of making a single pack. As long as you use good quality cells, the risk of a parallel group dying is incredibly small.

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.

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.

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.

Next, plan out your cell configuration on your computer or even with a pencil and paper. This will help ensure you are laying out your pack correctly and show you the final dimensions of the pack. In my top-down drawing below I’ve designated the positive end of the cells in red and the negative end of the cells in white.

It is possible to do it that way, however there are some compelling reasons not to. 1) By first joining all the series cells you would end up with multiple high batteries electrical groups, which means both the chance and consequences of an accident are greater. When you’re working with lots of exposed batteries with nickel conductors and metal tools flying around, the last thing you want is more high voltage possibilities for shorts. 2) Doing series cells first would be come unwieldy, physically. A series group is only connected at either the top or bottom of alternating cells. Without having multiple cells side by side to add stability, a long chain of single cells will need either a pile of glue or some type of physical holder to support the chain. and 3) most battery spot welders can only reach about 2 cells deep into a pack, meaning you’d have to either add very short nickel strips to each series group connecting only two groups (which means twice the welding and twice the cell damaging heat) or have long uncontrolled nickel strips hanging off the sides, again risking shorting.

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).

Actually, it is not recommended to use protected cells in ebike builds. There a few reasons but the main ones are 1) unreliability of the protection circuit, 2) many points of failure, and 3) lower discharge current of individual cell protection circuits.

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.

Hi Micah, thank you for your advice. I am not going to touch that battery. I know this may be a lot to ask, but would you build me a battery for my velomini 1 ? It doesn’t have to be the one that fits in the frame, I could put it in a bag and hang it on the handlebars or something. If more convenient you can email me directly at dlimjr at yahoo. My sincere thanks and may you and your family have a happy holiday.. Don, San Francisco

13. Winners will be emailed directly by the marketing manager. Must respond within a week. Winner may also be announced on Facebook.               14. Sponsor: The Sponsor of the Sweepstakes is Electric Bike Technologies LLC, 951 River Road, Croydon, PA, United States;

“diy battery pack |electric moped battery”

Also, since the negative electrode is the entire bottom and sides of the cell (formed by a metal cylinder) these cells can take some bouncing around. Be aware if you scratch the plastic wrap on the cylinder, the metal shell underneath is energized to the negative electrode, so…an electrical short may be possible.

We also maintain stock of replacement vertical seattube batteries that have been in use in the eZee bicycle line since time immemorial. If you have an eZee bike circa 2008-2012 with the Phylion lithium battery pack, you’ll be in for a serious upgrade with over twice the capacity in the same size and weight.

$Xport 350W 7 Speed Electric Bike Features: 350W motor, Samsung Lithium Battery 3 Riding Modes: Electric (Throttle, 3 speed), Electric with Pedal, Pedal Only Spec: Motor: 350W Battery: 24V Samsung Lit…

Nickel Metal Hydride is quite similar to Nickel Cadmium, but with a higher energy density and a safer environmental record when disposed of in landfills. This is the dominant rechargeable battery type in digital cameras and other consumer products that offer user replaceable cells.

To answer your question, you can definitely build your own auxiliary battery. It looks like they used a fancy right angled female XLR connector, but I imagine a standard female XLR connector will fit just as well. I’m not sure if you’ll be voiding your warranty though by connecting your own battery. Those XLR connectors can be purchased all over ebay and probably even at your local electronics shop.

I’ve been building a 13s6p Li-ion battery based on your article, and everything went swimmingly (except underestimating the amount of nickel I’d need) until I started hooking up the BMS. I was in the middle of hooking up the sense lines, and the BMS smoked. Opening it up, it looks like a few of the caps that couple adjacent nodes burned. Have you seen this before? Any thoughts on what I may have done wrong, or does this just happen sometimes when a cap’s voltage tolerance is outside spec?

BesTechPower makes some of the best BMS’s in the industry. You pay for that quality, but I believe it is well worth it. I haven’t used that specific BMS you linked to, so I can’t give you specific feedback on it. I haven’t done very many 7s packs, as that’s on the lower end for ebike use. The few I’ve done had some cheaper BMS’s and not the two wire design I mentioned. Sorry I don’t have any specific recommendations for you – it’s just a lower voltage level that I don’t often use.

LiFePo is 30 to 50% heavier and 10-20% more expensive than LiMn/LiNiCoMn. It’s safe but mainly, it’s got at least double the cycle life of LiMn/LiNiCoMn and seems to have an almost indefinite shelf life.

Combining the metals brings out the best in each. NMC is the battery of choice for power tools and powertrains for vehicles. The cathode combination of one-third nickel, one-third manganese and one-third cobalt offers a unique blend that also lowers raw material cost due to reduced cobalt content“

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 placed the first parallel group positive side up, and the second parallel group negative side up. I laid the nickel strips on top of each of the three sets of cells, bridging the positive caps of the first parallel group with the negative terminal of the second parallel group, as shown in the picture.

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. 

Ebikeschool.com has a lot of great info, but I’ve spent countless hours putting even more info, examples, how to’s, reviews, maintenance steps and buying guides into my book and video course. They are some of the most fact-dense and info-rich ebike resources available today. So check them out to see if they can help you with your own ebike!

I also soldered rather than spot welded and used 1.5mm2 solid core copper between cells, pre-bent to zig-zag shapes on a jig (current is then distributed between them). Offtakes were 4mm2. Soldering technique to minimise heat on the cells was to paint the cells and the wire with flux, load the soldering iron tip with enough solder to make the joint and then, while holding the wire on with the back of a wooden pencil, touch the molten solder to the cell/wire interface and immediately remove the soldering iron tip. This worked really well in terms of soldering quality and the solder cooled very quickly indeed. I cleaned the flux off with a baby wipe and then dried it with some paper kitchen towel.

2. I highly recommend using a BMS in both Li-ion and LiFePO4 batteries. As a Li-ion vs LiFePO4 question, one isn’t necessarily better than the other. Li-ion will be cheaper and probably more powerful, but LiFePO4 is going to last years longer, so it’s all about what you want in your battery.

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.

So let say main point to count the power is to count the power is to know what type of the controller i have (i have check my batt connection goes to PCB which has sensors it self and whole unicycle controller… ) how to know ? Or in primitive way i can count like my batt is 20A and 36W so max power can be 720W but its peak on continues?

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.

Love your youtube videos! I’m actually looking to make an electric longboard on the cheap. I have an 18V motor (from a battery drill) that I want to power and I have purchased 10 (AA) 3.6V 3000mAH Lithium-ion batteries with the intention of connecting them together in a series arrangement to run the motor. What would be the best way to arrange them? And is there a need for a BMS for a smaller arrangement? Or would it be more time effective/safer to just charge each battery individually? Any help is appreciated.

I continued with all 10 sense wires, placing the last one on the positive terminal of the 10th parallel group. If you aren’t sure about which groups are which, or you get confused, use your digital voltmeter to double check the voltages of each group so you know you are connecting each wire to the correct group.

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.

As a side-note, the Boeing 777 Dreamliner battery fire was using LiCo. They wanted a battery that was as light as possible, and as compact as possible. I am not an engineer, but I agree with the statement made by “Tesla” electric car maker Elon Musk, when he said that there was NOT adequate heat insulation between each cell. Better individual cell insulation would prevent a bad cell that was getting hot from heating up the surrounding cells. That is what led to a domino effect. The Tesla cars have a cell cooling system, and the on-board computer can detect and cut-off any cell-group that is getting hot.

aliexpress: http://www.aliexpress.com/item/e-bike-battery-24-volt-lithium-battery-pack-25Ah-for-backup/32446161781.html?spm=2114.031010208.3.9.x1znRh&ws_ab_test=searchweb201556_6,searchweb201644_3_79_78_77_82_80_62_81,searchweb201560_1

You are eligible for a full refund if no ShippingPass-eligible orders have been placed. You cannot receive a refund if you have placed a ShippingPass-eligible order. In this case, the Customer Care team will remove your account from auto-renewal to ensure you are not charged for an additional year and you can continue to use the subscription batteries for electric scooters replacement the end of your subscription term.

Lipo batteries are currently the “hottest” battery choice for electric bike enthusiasts. LiPo batteries are the most power-dense type of  battery available to electric bike riders today. The problem is that LiPo battery packs for e-bikes are hard to find, especially one with high output if you are building a racing bike for riding off road.

Thank for the great article. I made battery packs already, do you have any recommendations on chargers. I have a 53 volt pack 30 amp hr. I don’t know what charger to buy, and I’m worried as lithium batteries tend to blow up if not handled correctly.

3. Lastly, I assume if the BMS & battery were able to produce the 50A X 24V watts of 1200W that my electric motor would only ever use the 500W it is rated for? As in the E bikes controller would only draw around 500W?

Now this step is very important: I’m going to turn the pack upside-down and perform this set of welds between the positive caps on the second parallel group and negative terminals on the third parallel group. Essentially, I’m welding on the opposite side of the pack as I did when I connected the first two parallel groups. Skip down a few pictures to see the completely welded pack to understand how the alternating side system works.

As far as dimensions, I prefer to use 0.1 or 0.15 mm thick nickel, and usually use a 7 or 8 mm wide strip. A stronger welder can do thicker strip, but will cost a lot more. If your welder can do 0.15 mm nickel strip then go for it; thicker is always better. If you have thinner strips then that’s fine too, just lay down a couple layers on top of each other when necessary to create connections that can carry more current.

“e scooter battery _electric car batteries”

A very affordable 13S BMS that I like is this 30A version, though it can take a few weeks or even a month to arrive since it’s coming all the way from China. http://www.aliexpress.com/item/13-lithium-battery-protection-board-48v-lithium-battery-BMS-30A-continuous-60A-peak-discharge/1741121963.html

If you are concerned about the speed and power of an electric bike, pay attention to the motor size. Electric motor size is measured in watts and usually ranges between 250 and 750. When deciding on the appropriate amount of wattage, think about factors like the weight of the rider and the desired speed and terrain for the bike. If your child will mostly be on a flat surface, lower wattage should suffice; if they are planning to ride up and down hills, look for a bike with a larger motor.

Features: It is so light weight , easy to transport and to take it. It is eco-friendly and safe to use it. The battery holder is so stable and sturdy. Super powerful,safe and reliable. Suitable for bi…

Regarding the soldering of cells: generally it is not recommended as no matter how you do it, a soldering iron will still transfer more heat than a spot welder. That being said, I have seen packs that have been welded using both solid or braided copper wire. I’ve also seen someone use copper wick soldered to the cells terminals. It’s impossible to know exactly how much of an effect that the heat transfer had on the cells but if you don’t mind taking batteries electric bikes risk of some level of deterioration of the cells performance, then it technically is possible to solder the cells together.

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).

Ebikeschool.com has a lot of great info, but I’ve spent countless hours putting even more info, examples, how to’s, reviews, maintenance steps and buying guides into my book and video course. They are some of the most fact-dense and info-rich ebike resources available today. So check them out to see if they can help you with your own ebike!

Please see the video’s on RCgroups under LiPo fires. A simple 2200maH 3S battery pack blew the lid off a secured 55caliber ammunition can. Putting a LiPo pack in a closed metal case is a real “bomb” waiting to happen. See all the videos on RCgroups that show what happens when a battery is over-charged or over-discharged inside air-tight causes. The real solution is to make the case have a “preferred direction” of discharge……which can be very powerful. This is done by drilling holes in the case. But it stops the explosion factor. The best thing is to have a BMS on or inside the battery. Even if the cheapy Hobby King voltage monitor, that is much better than nothing at all. Also consider putting in a voltage monitor that has a temperature guage attached. When ever the pack skin gets above 85 deg C, you are in real danger of “vent and flames”. The temperature and voltage are that two big things that can make your battery pack safe………….also store the pack where if it does go to “vent and flames”, no human being will get burned.

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.

You’ll need someway to hold your cells in a straight line while welding, as free-handing is harder than it looks. I have a nice jig (that I received as a free ‘gift’ with the purchase of one of my welders) for holding my cells in a straight line while welding. However, before I received it I used a simple wooden jig I made to hold the cells while I hot glued them into a straight line.

Battery Model:36V 12Ah. New Lithium 36 volt 12 amp-hour Battery for Electric Bikes (e-bikes) and Scooters. Life cycle:more than 600 cycles. Battery Size (Approximate): 8″ x 3.75″ x 2.75″. Battery Weig…

I’ve been building a 13s6p Li-ion battery based on your article, and everything went swimmingly (except underestimating the amount of nickel I’d need) until I started hooking up the BMS. I was in the middle of hooking up the sense lines, and the BMS smoked. Opening it up, it looks like a few of the caps that couple adjacent nodes burned. Have you seen this before? Any thoughts on what I may have done wrong, or does this just happen sometimes when a cap’s voltage tolerance is outside spec?

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 😉

I was wondering, though, if I could use thick gauge wire instead of nickel strips (copper wires are much more accessible). Would there be any downsides to that, given that I’m going to be using solder anyway?

batteries e bike battery exide electric bike battery 48v battery 48v electric bike battery 24v battery gp battery 36v battery aw battery aeg battery ev battery 48v e bike battery 3c battery ima battery bb battery More…

Thanks for the info! I have read about builders that used Sony Konion LiMn cells that were removed from Makita Drill packs. The constant theme of their reports show that the thing they seem to like the most, is that the cells seem to just stay in balance. So much so that, several have built packs with no BMS. If there is a measurable LiMn shelf life issue compared to other chemistries, it doesn’t seem to bother the DIY pack building crowd.

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).

“electric bike batteries for sale _electric bike battery 48v”

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…“

Yes, that’d work, but I’d get an additional 7s battery so you have 20s total. Also, you should know that the older your original 48V battery is, the more time it will take your new 72V combined battery to balance, as the first 13 cells will likely have less capacity in comparison to the newer cells. I made a video recently showing how to do this upgrade that you’re talking about: https://www.youtube.com/watch?v=9KHo-T74IWA

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.

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.

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. 

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.

Lastly, regarding the spot welder. I actually prefer to use the kind like you said, with the two arms that lift up and provide equal pressure at each weld. The kind with two long welding cables like this welder has both options which is nice, especially for if you need to reach to the middle of a pack to make a repair or if you missed a weld. I mostly use the short rigid arms though and just weld one row at a time before adding more cells – that way I can reach all the cells with the short arms.

When you buy your battery, make sure you know what its maximum amp output is. Remember, by multiplying amps and voltage you get the actual current capacity of the battery. For example a 48-volt 25 amp pack can put out 1200 watts.

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.

This page is embarrassingly old, referencing chemistries that are completely obsolete, and is due for a rewrite. In the meantime, we recommend checking out our Battery Kits Product Info page for a more current explanation on lithium specific battery packs.

eBay determines trending price through a machine learned model of the product’s sale prices within the last 90 days. “New” refers to a brand-new, unused, unopened, undamaged item, and “Used” refers to an item that has been used previously.

12V increments are easier to do with LiFePO4 due to the 3.2V per cell. So for 12V, 24V, 36V and 48V they go 4 cells, 8 cells, 12 cells and 16 cells. Li-ion is more annoying because the 3.7V per cell doesn’t play as nicely. The general convention for the same 12V increments is 3 cells, 7 cells, 10 cells, and 13 or 14 cells. 3 cells is just a bit low for a 12V system (about 11V nominal) but will work for most applications until the voltage drops to about 9.5 or 10V depending on your device’s cutoffs. Regarding the balancing issue, if you’re using those packs that claim to remain in balance then I’d imagine you can just trust them. If their packs had problems with balance then they’d probably be having tons of returns. Worst come to worst you can occasionally open the case and measure the cells to make sure they are all staying balanced. One word of advice: be very careful with the series/parallel switch setup. If you make a mistake or the switch melts you could end up shorting your batteries and ruin the whole lot…

If you are thinking about building your own LiPo pack, a 48V / 10-Ah battery pack can be made for around $300. However to undertake this project you should research extensively on www.endless-sphere.com on how to build and take care of your pack. batteries for electric scooters replacement hours of reading before you are ready to build a pack of your own.

Rang: 18-25km(36v 6ah). Motor: 36V 250W brushless. Battery: 36V4/6AH lithium battery. The eco-friendly bicycle is 100% electric and emissions free, saving both your wallet and the environment. New Out…

I’m not familiar with this copper serial connection you’re talking about. I guess you mean to reinforce the series connections to handle more current? As long as you are using enough strips of nickel (and ensuring that it’s pure nickel and not nickel coated steel) then you shouldn’t need copper reinforcements. I try to use at least 1 strip of nickel for every 5A my battery will carry. So if I’m looking for a 20A max load, I’d use 4 strips of nickel in each series connection. That’s easy to do if each cell in a parallel group of 4 cells is connected to the next group by one strip each.

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.

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.

Used PL-350 electric bike kit, The battery does not charge. Charger is fine but only shows a red light. It sat dead for about a year. Then the controller showed about 80% after charging. Everything wo…

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?

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.

The only two ebike companies that sell LiPo to the public are Optibike and Pi-cycles, and both contain the battery in a strong metal box which makes up of the frame. The companies fire tested these enclosures and are confident that their frame are effective and safe vessels for LiPo storage.

However, when you factor in the shorter life cycle of lead acid batteries, they become comparable to lithium batteries over the entire life of the electric bicycle. For example, a lithium battery may cost five times the price of a lead acid battery, but it could easily last five times as long as well, making the price about the same over the life of the lithium battery. You’d have to buy at least four replacement lead acid batteries (maybe even more) by the time your lithium battery finally kicks the can.

If you are excited about this improvement in battery chemistry, (NCM being 25% smaller/lighter that the fussy LiFePO4, and 300% better C-rate than the reliable and non-fussy LiMnO2) you may also be asking the question…What chemistry is next?

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!

36v 10Ah Bottle Type Battery. Rated capacity: 10Ah. 36v 14Ah Rear Rack Type Battery. Rated capacity: 14Ah. 48V 14Ah Rear Rack Type Battery. Recommended to be used with 36V 250W electric bicycle motor.

So after buying a 48v 20 Amp battery from Ebay (and knowing very little at that point), I realized it didn’t have a BMS and heard rumors that if i attached it direct to the controller, it would see it as a short (controller would be closed) and blow the controller.

I then took my second sense wire (or your third sense wire if you have one more sense wires than parallel groups) and soldered it to the positive terminal of the second parallel group. Again, note that I’m soldering this wire to the nickel in between cells to avoid heating any cell directly.

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.

My thinking is that because each of the batteries is only 50% stressed, that the probability of problems due to overcurrent, etc. would be negated and I wouldn’t use a BMS for the supplementary battery.

I am new to the ofrum and to the ebike world so I would like to seek some advice please. I have recently bought a sondors fat bike to the UK and want to make some tweaks, I would like to upgrade the battery on a budget, I was thinking of 4 x 12v 5ah lead acid batteries in series, would this give me 48v 20ah or have I got this totally wrong? I want to replace the stock contoller for a 48v 25amp one, would this suffice? lastly it comes with a stock 350w bafang motor, if I make the battery and controller upgrades will the motor handle the increase in wattage? could I drill venting holes in the case cover to expell some heat? Your thoughts and advice would be most welcome,

For discharge wires you’ll want something bigger, like 14 awg silicone wire. 12 awg would be better but might be overkill for your use. For charge wires, 16 awg silicone wire would be fine and you could probably get away with 18 awg silicone wire.

I finally made it happen on BMS #3 (the unfortunate thing about AliExpress is that every dumb mistake that kills a part is another month added to the project) and the battery seems to work great, though it only has a couple miles so far.

First of all, NCR18650B cells cannot be discharged at 2C. Those are 5A MAX cells, and really you should keep them closer to 1C to keep them cool and happy. They are economical cells. They do better when in large parallel groups so you can take advantage of their high capacity without the downside of their low discharge rate. They are great cells, but not for low AH packs.

Many people are tempted to use cheaper 18650’s sold under names like Ultrafire, Surefire and Trustfire. Don’t be one of those people. These cells are often marketed as up to 5,000 mAh but struggle to get more than 2,000 mAh. In actuality, these cells are just factory rejects, purchased by companies like Ultrafire and repackaged in their own branded shrink wrap. These B-quality cells are then resold for use in low power devices like flashlights where their weaker performance is less of an issue. If a cell costs less than $2, it simply isn’t worth it. Stick to the name brand cells, like my favorite Samsung cells, if you want to build a safe, quality ebike battery.

“battery bicycles _electric bike replacement battery”

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.

Why do we alternate sides of the pack during the welding process? We do it because in this way we connect the positive terminal of each parallel group to the negative terminal of the next group in line. That’s how series connections work: always positive to negative to positive to negative, alternating between the two.

thanks for detail explanation , I was enjoj reading it. Well, I am interesting why did you pick this tipe of battery, I was thinking to use LiFePO4, I know there are usualy 3.2V it is less than 3.6V like here? Also, can you explain me how to calculate max current of battery, it says that you get 8.7Ah, but how much Ampers and what is the power of battery, how many Watts (P = U * I)? Furthermore, without welding, can I do on contact connection, like for example are battery in remote control?

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.

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.

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

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.

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.

The only two ebike companies that sell LiPo to the public are Optibike and Pi-cycles, and both contain the battery in a strong metal box which makes up of the frame. The companies fire tested these enclosures and are confident that their frame are effective and safe vessels for LiPo storage.

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.

There is a recently introduced battery chemistry that we will likely be seeing a lot of soon. Lithium-Nickel-Manganese-Cobalt-Oxide, or LiNiMnCoO2/NMC. Since Asian battery manufacturers have been working on a wide variety of alternative chemistries, a manufacturer standards group has chosen the  abbreviation NMC for this chemistry (although one wholesaler stubbornly calls it NCM).

Furthermore, if you have more capacity than required, then you also have the opportunity to do partial charging of the battery with a Satiator or similar device, so that instead of charging the pack to 100% to squeeze out every km, your standard charge is set to a lower 80 or 90% level. This can have a pronounced effect increasing  both the cycle life and calendar life of a lithium battery by several fold. 

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. 

I wouldn’t say incompatible but us 220 uses the full phase peak to peak of both legs of the elec drop. European and others uses a half phase (I believe) where zero to peak is 220v. Have you had a chance to look into this for me as my welder and box of new 18650’s are sitting idle waiting for me to start welding. Thanks

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.

Here at Grin we’ve been dealing with ebike batteries for a very long time during which we’ve offered over 100 variants of NiCad, NiMH, LiFePO4, LiPo, and Lithium-Ion packs in all kinds of voltages, geometries, and capacities. It’s been a love/hate relationship over those years, but the more recent mass production of 18650 lithium cells for high power consumer goods like power tools has shifted things to the love side, with ebike batteries that are cheaper, lighter, and with far longer life span than we could have ever wished for in the past. We’re happy to stock both frame mount and rear rack mounted batteries from 98 watt-hours to 1100 watt-hours in size to suite the needs of most electric bicycle conversions. 

Nominal capacity: 12Ah (Fully charged after 0.5C discharge to 38V capacity). Cycle life: Standard charge and fast discharge cycle 500 times, the capacity will notless than 60% of the nominal capacity.

Well, you’re right that I wouldn’t recommend it! I admire your ingenuity but there are a couple big issues with this setup: 1) You have 4 groups of 10 series cells but no way to balance between them. The 4 cells need to be paralled before they are wired in series otherwise they will get increasingly out of balance with each charge/discharge cycle. 2) I’m not sure you’d get a good enough contact from a copper spring or busbar that is just held on the end of the cells in compression. The copper will also corrode over time and caused increase resistance at the point it touches the cells and problems down the road.

Yep, that explains it. I was going to say that it sounds either like a defective BMS or more likely a connection error. B1 is definitely the negative end. Also some BMS units have B1- and B1+, others just have B1+. If it has both, it will have X+1 sense wires, where X is the number of series cells in the pack.

I want to build a 36v ebike battery for my 36v 500w motor. What battery you recommend for me which gives the enough current and capacity. My plane is to build a battery with 40 cells 10 in s and 4 in p,

Lastly, regarding the spot welder. I actually prefer to use the kind like you said, with the two arms that lift up and provide equal pressure at each weld. The kind with two long welding cables like this welder has both options which is nice, especially for if you need to reach to the middle of a pack to make a repair or if you missed a weld. I mostly use the short rigid arms though and just weld one row at a time before adding more cells – that way I can reach all the cells with the short arms.

How do you determine this exactly? Your battery is a 36v 8.7Ah and I guess it has something to do with the maximum continuous discharge rate. It would help me (and maybe others) to explain why 30A is more than enough for this battery.

LiMn/LiMnO2-Lithium Manganese Oxide. Adding manganese to the cathode made this chemistry more stable and less sensitive to individual cell balancing issues. If you were using LiFePO4, and one cell began losing its amp-hour capacity, the rest of the pack would get dragged down to the weakest cells level. Demanding high amps with one weak cell in the pack would cause the entire pack to wear out much earlier than it should have.  With LiMn, the packs just seems to stay in balance, with all the individual cells aging equally.

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.

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…

Its low C-rate of 1C means you need a large pack if you want higher amps. Justin at ebikes.ca was an early adopter of LiMn for his E-bikes because his customers wanted a trouble-free product that wasn’t fussy and lasted a long time. Makita cordless tools use LiMn, as do many laptop computers. Last year Zero E-motorcycles were using LiMnO2, but this year they moved up to NMC (found listed below). [edit: Due to customer desires and safety concerns, LiMn has been improved and now in 2014, there are high current LiMn]

I would prefer to go with lithium, but I have a couple of 75 volt (i think) cells from a UPS that are brand new. They are built from regular 12v (sixteen total) sealed lead units and would make the initial investment in an ebike that much more reasonable. One huge downside is that I hope to use the folding ebike in my homebuilt aircraft. As with ebikes, excess weight is to be avoided!

Battery packs are made up of individual cells connected together. Each cell has a more or less constant voltage dependent on its chemistry. For NiCad/NiMH, this is about 1.2V, for lead acid it is 2.0V, and for lithium cells it is on the order of 3.7V. Typical ebikes and scooters are designed to run on 24, 36, or 48 Volts, so a number of cells have to be series connected into a ‘battery’ that has the desired net voltage. A nominal 36V pack could be made from 10 lithium cells, 18 lead acid cells, or 30 NiMH cells.