Is there anything wrong with a DIY 4s4p or 4s6p battery

ESK8 Electronics
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Hi everyone,

I’m building up my own e-skateboard and I’m really just going for a top speed of 20kmh (12mph). I don’t see myself ever riding this faster than that, and I’m only planning on riding it for commuting to work. (10km one way).

I’ve been looking at battery configurations and it seems like no one has done 4s4p or even 4s6p arrangements for e-boards. Is there a reason for this?

Also as a side note, the way I’m planning on arranging my batteries are like this so that it’s as thin and small as possible (red is just a barrier): image.

Thanks for the help everyone!

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The problem with lower voltages is you get more current and more heat. You’ll have to design your system to handle the extra heat with thicker wires, more nickel strips if you’re going the DIY battery route.

Its not just a theory. In practice your motors and esc will also have to dissipate much more heat.

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If you’re going to use 16 cells then an 8S2P would probably work better, and if you’re going to use 24 cells then a 12S2P would probably work better.

Why do you want to use 4S?

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I don’t care for speed as much as I care for capacity and range. I’m assuming 4s is plenty to get me to 20kmh top speeds.

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You’ll probably still be better off with more than 4S.

Range will be mostly determined by number of cells, which cell, gearing/top speed, riding style, and rider weight.

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Oops where are my manners? Welcome to the ESK8 community, @SaveKony2k21

Stacking more cells in parallel vs in series doesnt get more range. The total number of cells and the capacity of those cells is what provides range.

I’m with @b264 on this one. It would be better to do 8s2p and go for a lower kv and optimized motor pulley ratio. Dont aim for a smaller motor pulley necessarily it will only wear out quicker. But if 12mph and long range is your goal, aim for a lower kv and a very high tooth count on the wheel pulley.

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Ok, thanks a lot for the explanation! I’ll probably go with a 6s4p then.

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Again that would create a lot of heat in your system. And it might toast your esc.

Just to give an example, say you want a system that can feed 5,000 watts to your motors.

6s 22.2v would pull 225 amps.

While

12s 44.4v would pull 112 amps.

Higher voltages are much more efficient in terms of heat losses. This is why full size EVs use several hundred volt battery packs.

You’d be wasting a lot of energy as heat and it would shorten your boards range. And thats assuming it can handle the amp draw in the first place.