I have a REC active BMS on my 800ah Winston cells 2P4S setup. It's been working great, SOC match my Victron BMS, cell being balance ... However after I upgrade my battery bank to 1200ah, 3P4S, I've cahnged the set up on the PC software, change to 1200ah capacity, since then SOC calculation is totally out. On the Bluetooth app still showed 800ah instead of 1200ah. What di I do wrong?
did you use the CAPA parameter to change your capacity?
Go to the manual commands section in your wifi or PC software and try:
CAPA 1200 <enter>
it should respond with OK
To verify, type:
CAPA?
it should respond with 1200
Your BMS will need to full cycle a few times before your SoC becomes accurate but you can also manually set it using the SOCS command like this
SOCS 0.75 <enter> will reset it to 75%
I set my battery capacity at the above circled spot on the PC software. After set up there it still show 800ah on the phone app.
If 183Ah use, SOC should be only ±85%??? 100-(183÷1200x100%)