Battery costs and suppliers

Mine are from a Kia soul, better form factor for a board. Given the specs in the leaf one I would say its two cells in series in that box.

Thats a nice way of saying “your battery is going to be double as heavy”. A 18650 cell has roughly 45g and 3Ah. Those got 300g and 8Ah. So same weight for 18650 would be ~20Ah…maybe a bit less because of more pieces => more cell holder and connectors.

Also I would trust a cell with a steel housing a lot more than a coffeebag/pouch…no matter if it is LiPo, LiIon or LiFePO4.

Also did you see any datasheet, discharge tests or cycle tests?

I agree with the first argument but I disagree with the second.
Pouch cells are not so easy to use for the 0815 mechanical expert but they can handle a lot more than a cylindrical one.
I am using a pouch cell which deliver over 250A continiously…1 cell in Series😃
No joke but you need some skills and not a China BMS and not a RC toy charger…

Electrically, yes
but how do you fix them inside the board? How do you connect them? How do you isolate the connections?
How do you ensure that nothing spikes or rips at the thin foil?

I connect them with industrial cable stuff. Wach cell ist wrapped in a polymide film. The cells are connected in series with a screwed bar made of aluminium.


This is one pack of the three shortly before the housing was applied. I have uses foam…

Check out my battery build. It’s a long thread, but there is a lot of good information in there.

I bought 200 Samsung 30Q cells for $750. 196 cells for 14s14p.

:call_me_hand:

which is also just a thin foil, one spike and the party starts… not so easy with a steel cylinder.

and how do you isolate those busbars against each other? I mean sure you put tape around them, but while driving they will wobble and maybe even rub against each other…again a party starter…

No there is no wobble. This kind of pack is user in Paragliders. I have crashed the board twice on a rock…the most important is a good compartement.
But if you use the cylindrical ones it is also good. But if one cell is damaged in a parallel row :crazy_face: have some fun

If you would like a very low cost solution for your first build:

hi, what Kind off brand? kokam?
thanks for info. my level of knowledge after 8 years of building aircraft: so far there have only been cells up to 150 A continuous load and 40 Ah in aviation. Of course, the cells can only deliver up to 220 A for a short time, and the cycles / life is then reduced dramatically.

I use the SLPB120216216, it is not RC stuff as you can see :wink:

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You meant to say 1 cell in parallel? One cell in series would be only a 3.7v battery.

I suspect you have 12-14 cells in series. And only one cell in parallel?

Cool to see people getting creative with different battery designs. My first battery works so well I’m building another just like it.

:call_me_hand:

Hello Fabian,

where do you buy these kokam cells?

ähh, sorry, ONE CELL parallel and 14 CELLS SERIES :wink:
my mistake…
to buy them it is really a challenge….

so you battery is around 16Kg?

Yes, 16.24kg…plus the BMS, some foam, some connectors,…17kg.
But it is a battery in 3 pieces. Important to keep it flat.

:exploding_head:

My battery is only 6.3Kg and I get an hours ride time! Why would you want a 17Kg battery…

because I am not driving an efoil….so I need the 200-250 A for a longer period.
And a 1P configuration is better to handle than a 10-16P config - no drift in the parallel row :wink:

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thanks for the information. I suspected that you meant this kokam type of cells. i know these from e gliders. the weight is not so important there. With e-ppg these cells are 40% too heavy. therefore we use 18650 or 21700 cells li-ion. yes, the industrial version of the kokam cells is the best on the market worldwide. Best regards

You are right, different application different battery :smiley:
I like the Kokams…you can handle them without care (BMS) and they are delivering more than mentioned in the specs…