80A BMS for 75 A battery

[gdinim]

I am building a 36V 10S 75Ah battery, I have not succeeded in sourcing a 36V 10s 75 A BMS, can I safely use a 36V 10S 80A BMS with an 80A over current protection

http://www.batterysupports.com/36v-37v- ... p-389.html

[Joachim]

How many cells in total? and the brand/type cells?

[Punx0r]

I think you're mixing up A (power) and Ah (capacity).

What load is this battery going to power? This will determine how many Amps your BMS needs to be rated for.

[flippy]

the bms needs to be rated for the limits of the battery, not it's application.

[gdinim]

the cells are Samsung 25R the battery is 10s 30p for 75Ah powering two 20A controller for 2 500w geared motors

[fechter]

The BMS should be rated for something above the intended load. In your case, it looks like 40A. It's good to have a little more so the peaks don't cause the BMS to trip. I'd look for a 50A or more.

The BMS normally does not limit the current. It acts like a circuit breaker if the current goes too high and cuts off. The controller limits the current, so you just want the BMS to handle that much.

The capacity of the battery is very large, so you will have no problems with the cells overheating. Most Li-ion cells can handle at least 2C discharge, so your pack could do as much as 150A if you wanted. This would be the most your BMS should be rated. You want it to trip if the load gets high enough to damage the cells.

[flat tire]

That is a gigantic battery that could out hundreds of amps without hesitation. No problem with a 80a BMS.

The 80a means current output, not storage capacity which is the current a battery can put out for an hour before being depleted (amp hours). The entire purpose of a BMS is to protect the battery so you don't want to use one that can let your battery try to supply or receive more current than is healthy.

[999zip999]

300 cells ? Is this a two wheel drive nature bike.

[gdinim]

I live in a rural area on Cortes Island short steep hills, I am making myself an electric bike with a long side car, all one piece.
Motors on front and rear wheels of the bike. I will be able to carry a passenger or a load of seaweed for the garden or firewood