Which bms should I get

[GreenLeoMan]

I've got a 20s 16p (72v-40ah) battery pack consisting of samsung inr18650 25r cells. Each cell says it's 2500mah and 20a. I want to go with a daly bms but i don't know what amps to go with. I don't know the math. Any help would be great. Bigger=better. I haven't picked a controller yet as it depends on the bms. My motor is a 17inch qs 8000w.

 

[lnanek]

20A max continuous discharge per cell * 16 in parallel = 320A max for the battery pack, assuming all the connections between the cells can support that. You could discharge it into a test load and check with a thermal camera if you want to be sure. It's already over 3x your motor's spec anyway at that point, though. So I think motor would overheat at that current.

 

[GreenLeoMan]

20A max continuous discharge per cell * 16 in parallel = 320A max for the battery pack, assuming all the connections between the cells can support that. You could discharge it into a test load and check with a thermal camera if you want to be sure. It's already over 3x your motor's spec anyway at that point, though. So I think motor would overheat at that current.

I'm sure it would. I wasn't planning on putting the max to the motor. 200a is pushing it. the motor has a peak of 260a so a 300a bms set to 200a and a fardriver nd72680 set to the same should do just fine without getting things too hot. Tnx a bunch.