How to coordinate multiple bms?

[NapalmFist]

I have a question about how I am supposed to setup my battery bank BMS. I ordered 64 LiFePo4 batteries and will be making 4 series of 16. I will be putting one 16s bms for each of these banks and then paralleling them into pairs because I want to have 1 bank go to each Luxpower lxp6k (same as eg4 6000xp) and I will be getting 2. I was going to buy JK BMS, what current capacity should I be looking for? The mppt put out 125amp max each. Also, is there a way to have all for BMS communicate with the inverter/mppt since I believe there is only 1 communication port for this or do I simply not connect them?

 

[sunshine_eggo]

If these inverters are operating in parallel, they need to be connected to the same battery.

If so, I would build 4X 16S batteries each with its own JK BMS of your choice and wire the four individual batteries in parallel to feed the inverters.

This gives you individual cell data and will allow you to remove a battery with a failed cell and continue to operate on the other three batteries.

 

[SilverbackMP]

I have a question about how I am supposed to setup my battery bank BMS. I ordered 64 LiFePo4 batteries and will be making 4 series of 16. I will be putting one 16s bms for each of these banks and then paralleling them into pairs because I want to have 1 bank go to each Luxpower lxp6k (same as eg4 6000xp) and I will be getting 2. I was going to buy JK BMS, what current capacity should I be looking for? The mppt put out 125amp max each. Also, is there a way to have all for BMS communicate with the inverter/mppt since I believe there is only 1 communication port for this or do I simply not connect them?

ideally for closed loop communications, you’d have a master/slave BMS setup with BMS units that support it.

For open loop, no communication is required.

 

[NapalmFist]

If these inverters are operating in parallel, they need to be connected to the same battery.

If so, I would build 4X 16S batteries each with its own JK BMS of your choice and wire the four individual batteries in parallel to feed the inverters.

This gives you individual cell data and will allow you to remove a battery with a failed cell and continue to operate on the other three batteries.

Thank you for this, I didn't realize the inverters/mppt needed to be connected to a single bank. If they are connected to a single bank is the charge capacity doubled (each has 125amp charge capacity) meaning 250amp or is it just charging at 125 amps? Because I assume this makes a big difference for what current capacity I need to buy for the BMS right?

 

[sunshine_eggo]

battery capacity and current ratings stack when in parallel. Since current sharing between the batteries won't be perfectly shared, you can't count on 100%, but 200-225A in your example should be very reliable.

Again, I would build FOUR separate batteries, not two. Avoiding the cost of two BMS in a system of this scale is false economy.

 

[hardtop]

I'd like to see your setup when your done. How many ah cells did you get?