Battery Bank - wire for 12v, 24v, or 48v?

I just did a battery revamp and added 4 lithium batteries, stayed with 12v setup due to pre-existing 12v inverter charger. Very happy with it, They don’t sweat high draw loads, but i’m finding that my Victron 702 is not an accurate indicator of charge. I think it calculates it based on amps out but doesn’t seem to jive with the readings I see on each of the batteries via their BMS panel. Some tweaking to do there. Agree that amps in and out will be the main indicator, but not sure yet how to accurately show that via the 702.