Ebike Battery Cell Layout Questions

Batteries, Chargers, and Battery Management Systems.
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skyeg3   1 W

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Ebike Battery Cell Layout Questions

Post by skyeg3 » Mar 05 2020 4:15pm

Hello ebike battery builders. I am going to try making my own battery packs for fun and to save money this time around for my electric atv project. I bought some batteries from Em3ev a few years ago and I want to use the same form factor as those. The packs are 5s20p. So 72V. At first I tried putting the cells into the form factor of the battery vertically (pink) as shown in the pic attached. I also put the cells in horizontally (orange) and I like how that fits better. Does anyone know if there is any issue with stacking cells like this horizontally? I like that the end connections wont bear weight on them in the horizontal configuration. These batteries will also stack two tall, increasing the weight on the lower battery. What configuration would you use?
battery pack.JPG
battery pack.JPG (107.05 KiB) Viewed 309 times

john61ct   100 GW

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Re: Ebike Battery Cell Layout Questions

Post by john61ct » Mar 05 2020 8:01pm

72V means 20S not 20P.

5P * cell mAh gives pack Ah capacity.

Orientation is no issue so long as terminations are well insulated / contacted electrically as appropriate, and cells, wiring, BMS etc all well protected physically from shock / vibration.

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amberwolf   100 GW

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Re: Ebike Battery Cell Layout Questions

Post by amberwolf » Mar 05 2020 11:22pm

skyeg3 wrote:
Mar 05 2020 4:15pm
The packs are 5s20p. So 72V.
just to make sure you understand before you build your batteries, 5s is only 21v fully charged, 18.5v nominal.

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