I want to add a BMV-700 to an off-grid system with another manufacturer's inverter. When the Charge Voltage Setpoint is set, does it compensate for bulk and absorption charging before displaying 100% SOC. In other words, will it display 100% SOC as it passes the Charge Voltage Setpoint while charging, or is it smarter than that. I own another manufacturer's monitor that is not that smart, so I want to make sure.
You program your charged voltage and tail current. Once those criteria have been met for X minutes, it will sync to 100%.
Charged voltage should be 0.2V below absorption if charging by solar or other variable power method. If charging with reliable and consistent current, 0.2V below float.
Tail current should be slightly higher than your battery's specification, i.e., if you're using lead acid, and they are fully charged at 0.02C, then set BMV to 3%.
If you're using LFP, LFP is fully charged at absorption and 0.05C. In this case set tail current to 6%.
You also need to set Peukert appropriate for your system. It defaults to 1.25, and that's generally good for lead-acid. If using LFP, set to 1.05.
It also "counts" current while charging, so it may indicate 100% simply because it has counted enough current to restore 100%, i.e., if you use 20Ah, have charge efficiency set to 90%, and then you charge it with 22Ah, then it will simply count back to 100% without actually synchronizing. In my experience, this happens FAR more often than an actual "jump" to 100%.
