An electric bike battery is a power storage medium for use with electric bikes and electric trikes. An electric bike battery can be a lead battery, or a lithium type battery similar to those in laptops, or cordless power tools. A lead electric bike battery is usually of the type called SLA, which stands for sealed lead acid. A lithium electric bike battery may be one of several types. The most commonly used lithium electric bike battery types today are Lithium Iron Phosphate (LiFePO4 or Life) or Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2 or NMC). The E-Bikekit lithium electric bike battery is a Lithium Nickel Manganese Cobalt Oxide type battery. Considering the size and weight difference between LFP and Li-NMC, all lithium packs are Lithium-Ion, but not all are the same energy density – LiFePO-4 batteries are larger and heavier than Li-NMC.
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.
The next consideration is ensuring that the battery is large enough for your required travel range; it’s no fun having a battery go flat before the end of your trip. In order to determine the range that you will get from a given battery, you need to know both the watt-hour capacity of the battery, and how much energy you use per kilometer. Sounds complicated? Not really. As a rule of thumb most people riding an ebike at average speeds consume about 10 Wh/km from their battery, and this makes the math very easy. If you have a 400 watt-hour battery, you can expect a range of 40km. A 720 watt-hour battery? ~72km
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.
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It is also possible in principle to series connect two 36V batteries to make a 72V setup, but the only battery we have that is intrinsically designed for this is our LiGo modules. With all other batteries, it is essential to use a pass diode across the output of each battery so that when one BMS circuit trips it does not get exposed to a large negative voltage. We have a special series battery cable with this diode built in available here.
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.
Yes, that’d work, but I’d get an additional 7s battery so you have 20s total. Also, you should know that the http://twowheelev.com 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
The biggest advantage of lead acid batteries is their price: dirt cheap. Lead acid batteries can be purchased from many different online retailers and local stores. Purchasing SLAs locally helps save on shipping and makes them even cheaper. Many hardware and electronic stores carry them. Even Radioshack has them, though you’ll pay more there.
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
I figured this would be a critical step I wouldn’t want to mess up. Thanks for the advice on using the multimeter. That’s good to know as I thought I might need to open up the controller and see which wires went where on that male xlr connection which I guess would be an option too. Thanks again!
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.
HERE ARE 50 GENIUNE MOLI ICR-18650H 18650 CELLS. THESE WERE TESTED IN ONE OF OUR LIITOKALA TESTING STATIONS AND THESE ARE ALL BETWEEN 1201-1400MAH! THEY ARE UL LISTED CELLS AND MANUFACTURED IN CANADA …
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…
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)
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.
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.
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…
When choosing a battery for your bike, not only is the weight important but the volume is also important. You want your pack as small as possible so its easy to stow and easy to hide. So therefore you should consider you battery’s volume, not just its weight. For sure you need to go with a lithium chemistry and not an old school heavy and large Sealed Lead Acid (SLA) or Nickel-Metal Hydride (NiMH) chemistry.
When I’m experimenting with some new ebike parts and want to test different battery voltages for different speeds, I often use lead acid batteries because I can try many different voltages using very cheap batteries. Then when the results of my lead acid battery tests show me whether I want to go with 36V or 48V or 60V, for example, I then commit to buying the appropriate lithium battery.
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.