I've had a couple days now where my EG4 Wallmount Indoor 280Ah battery goes from 23 to 0% and kicks in AC charging. I've plugged in the BMS Tools via the RS485 cable, and there are no alarms before this happens. The app crashes after a bit so I can't let it run overnight to see more detail.
Any idea what would cause this? I have charged to 100% in the last 4-5 days, so the BMS should be calibrated right?
... I have charged to 100% in the last 4-5 days, so the BMS should be calibrated right?
You may have reached a 100% charge but did you reach a full charge? One easy way to know if you actually fully charged your battery (and thus reset the BMS SOC reference point) is to look at whether or not the master battery signaled that the battery bank is full, by lowering the BMS Limit Charge parameter. You can look at your data history for the parameter named "MaxChgCurr(A)" at the time you think you achieved a 100% charge to see if this happened.
You can use open loop (lead acid) control to get to a full charge, but you can also do it using closed loop comm if you get your settings right, and you can use this BMS Limit Charge parameter to know if you're getting there.
To recalibrate the battery, you’ll need to charge it to 57V using either a 48V charger or the inverter set to Lead Acid mode.
Are you regularly charging and discharging the battery to an 80% depth of discharge (DoD)?
Here is a link to the recalibration guide.
@eg4eric If we have 2 Wall mount batteries do we need to recalibrate them individually?
Or can we charge them both to 57Volts?
Should we disconnect the communication line or leave it plugged in?
@powerup
You can charge both at the same time to 57V, the communication cables can stay as they are.
I've been trying to keep it from 100 to 20, but it regularly goes to 8-10, even though I have the inverter cutoff set to 20%. It may need a calibration. I'll follow those instructions and let you know if something changes. Thank you, Eric!
Do I keep the SOC settings for charging and discharging, just up the absorb to 57?
@michaelahess
Once you change the inverter to Lead acid, the SOC parameters will not matter since it's going based off of voltage. So, you will need to set the absorb voltage to 57V. The SOC can stay the same.
