Battery and BMS

Build, Repair & Mod
1

Still into the design phase of a new JetBoard.

I am running twin MHZ 58s with Scorpion HK-5035/760KVs.

The Scorpions are capable of 185A Continuous and 230A Peak.

I am running a MakerX 300A Beast VESC for each motor.

I now need two batteries (one for each).

I am thinking 10S12P Samsung 40T;

That gives me 48Ah and 300Amps.

I am looking at this BMS;

Allegedly, this gives me 200A continuous and 500A peak.

So, I have a minimum of 200A continuous right through the electric power train.

I have read through the forums that the LLT BMS are OK?

Thoughts? Advice?

2

Seems the 40T rating in this test was estimated at 25A, pack current for 12P at 300A (but with temperatures that would damage batteries to some degree)

600Ax36v is 22kW, it’s a lot of power so i guess you won’t be running this continuously (packs will be depleted in 10 minutes)

I think it looks good, a small questionmark on the makerX capability, if it’s truly capable of this power level continuously. ESC’s are almost always overpromised. Good cooling of all parts in the powertrain needed!

3

The Scorpions will probaby be running at ess than 100A on cruise.

Motor and ESC will be cooled, but not sure about the battery. I note that no one on these forums allows for any battery cooling.

4

Se here, @ 14:00 he talks about heat management.

1 Like
5

True, the fundamental difference is that most of us also run large batteries and that combined with the relatively low power needed to run an efoil means that the heat created is low.

6

Thank you so much for this - really helpful.

I will add cooling to the battery compartment.

7

Good point. Short bursts of high power and then cruise.

8

An easy way of making use of cooling is to make the bottom of the board part of the battery case (so it will be cooled by the water underneath it)
I never had problems with heat when I was running my jetboard on 6S. The heating problems started when. I started using 12S.

9

Easier said than done. Maybe a heat transfer pad between the battery and the bottom of the board to make sure that you have good contact. Then you have to clamp it down some how.