I am installing two lifepo4 batteries of 15kw each with a multiplus of 5000va and 48v. The BMS of one battery comes uncalibrated and the seller recommends me to charge and discharge the battery to the maximum to calibrate it. How should I configure the multiplus for this operation? Should I leave the other battery that is correct in parallel while the other battery is calibrated? Regards
Multiplus charger only parameter is voltage, input the correct voltage for your pack.
Do not connect in parallel 2 pack that have a very big SOC difference or you could see a big rush in current.
Charge independently the 2 pack to the same voltage, then connect them in parallel, then charge to max voltage, the bms will certainly reset it SOC to 100% when reaching max voltage (total or per cell, depending on the bms)
If there are no better instructions from the supplier. This should work.
Setup single battery correctly in multiplus
Disconnect calibrated battery.
Run multiplus in inverter only mode until it cuts out from flat battery (I assume the BMS will disconnect the battery once depleted).
Switch multiplus to charge only and charge until BMS cuts the charge current.
This will take some time due to battery size.
Optionally and preferably repeat for 'calibrated' battery. Even if you don't discharge fully, at least charge it on its own until it's full.
Connect both batteries to multiplus.
Setup for dual batteries.
First of all, thank you very much for your response. The uncalibrated BMS reports that the battery is at 1% when, due to the voltage it has, it should be approximately 60%. Depending on your instructions, the BMS will either cut off the discharge almost instantly or simply not discharge at all. Once in charger mode, when the battery is 100% charged, we assume that the BMS will cut off the charge. I hope I understood. I only have the doubt whether the multiplus in charger mode will not interfere in the process by cutting off the charge due to its configuration parameters. I'm also not very confident about letting the BMS cut the charge because of the problem it has. Although it is supposed to be configured correctly, I will have to check the configuration of the latter. All the best
