is a 250A Dialy bms enough to make a 300ah battery

[Pie]

Helo! I have 12 lifepo4 batterycells of each 100ah, 3,5volt and i want to make a batterypack of 300ah. I ordered one 4SDaily BMS of 250A. Can i use it or is it to small? Somebody has a plan for this setup? Kind Regards Pieter

 

[mikefitz]

I ordered one 4SDaily BMS of 250A.

The BMS current handling capacity depends on the load and charge currents you expect to use. Yo could build a 300Ah battery and use a 100A BMS if your currents are below 100 amps. The general opinion is with FET based BMS control circuits, a degree of derating should be used for continuous current.
examples of 3P4S batteries found on the forum,


Mike

 

[rmaddy]

To further add to what Mike stated, the size of the BMS has nothing at all to do with the capacity of the battery. You could build a 900Ah battery or 100Ah battery with the same BMS. Remember, Ah is amp-hours which is the capacity. The BMS rating is for amps which is an amount of current. Two different units measuring two different things.

Your 250A BMS should allow you to use up to a 3000W inverter (3000W / 12V = 250A). Of course if you were to try to fully utilize the 3000W for a while, your 300Ah battery will be 100% used in just over an hour (300Ah / 250A = 1.2 hours).

 

[chrisski]

I have a 24 volt, 50 ah 1200 wh pack with a 15 amp BMS. Perfect for what I need. I wanted to deliver no more than 15 amps to cover 300 watts continuous on an inverter.

If you’re going to use a 250 amp BMS, probably need some thick wires 2/0 to handle that. Also some thick busbar.