I’m planning to build my first electric longboard and I’ve done all the research that is needed.
The only thing is what batteries to choose. I was planning on 10s4p. Would these batteries be enough for a dual motor/dual vesc setup with a 60A BMS? is 10C discharge rate enough or should I get a higher discharge rate battery? I’m trying to build the highest capacity battery pack with these cells http://www.illumn.com/batteries-chargers-and-powerpax-carriers/batteries/18650-sanyo-ncr18650ga-3500mah-high-discharge-flat-top.html
10C is more than adequate at 4P. thats 140A continuous draw.
and considering that you are going to use a 60A BMS you should never see that kind of current anyway.
Im actually using these sort of cells for my mountainboard build but I have 6s6P pack
If you dont expect to draw more than 400w regularly, you might be okay but you are basically very close to the recommended limit.
Also depends on do you plan to go uphills.
For me power draw going up hill usually is about 30-40A (~860 W max)
And I’ve got single drive.
It has been said that ‘‘safe’’ / good power draw is about 3A (~1C) per cell, so in your case that would be 12A total, 6A per motor.
at 36v (10s), that would give you 216W per motor, and 412W total.
So if you go only on flats and not more than 30-35kph, it might be enough…
I dont have data on hot hot they become, but Ive heard they start to become hot if you draw 7A per cell from them and… reasonably, capacity then is also lower.
For 4P pack, Samsung 30Q might be your best bet, you would get the desired 60A, would still be very close in capacity Sanyo’s GA anyway, as I think they deliver more like 3.250 mah not 3.5ah as advertised.
So yeh, with samsung 30Q pack, at maybe 2.8ah usable capacity, you would still get 36v x 11.2ah = 403.2 Wh
For longboard this might be a huge range… something like 40km probably or 25miles.
Seems okay to me! I know vapers use these a lot and also @whitepony used them… so far… Haven’t seen anything bad being said about these cells…Not sure are they the newest… but should perform decently…
If you do wish to study batteries thoroughly, I recommend for you to visit this site:
You can quickly take a look at different specs of different make batteries.
The site is a very good reference point to see whenever the choosen cell will perform as you ‘‘planned’’.
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In short - cell is quite good, the price would be the one which bites! Ask @PXSS whenever it is still possible to get 30Q cells for a low price. He managed to order some from Nkon internatioal site for quite a bargain… ask him whenever it is possible to get 30Q… but if you are very forward with getting ‘‘officially’’ stated 20A cell… then go with HG2 cells or similar, even though it looks like 30Q performs good enough for not high enough / maximum loads.
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Looking at this, it looks like 30Q performs a bit better than HG2 actually but im not informed about the temprature these cells face at these discharge levels!
Im not sure do you regularly need more than 10A per motor (total 20A for 4P pack @5A per cell… So that is why I chose 5A, but for 7A it is similar, the capacity might be a bit less
