vshitikov said:
This handling is not ideal but I guess it's the only one possible if you don't have a smart BMS that communicates with your display.
If that really is the case, then i'd call it useless (for my application). For battery life, I very seldemly charge to 100% (or even 90%). I try to keep my SOC at 50% and then top up a little and only fully charge if i'm unsure about the needed capacity.
Building an internal table that relates every (loaded) voltage to a specific SOC would at least give a very good estimate, that would need recalibration every now and then.
Let's say you have entered a 1000Wh battery, and 60V 100% SOC, with a LVC of 42V. And as you count Wh, note the voltage at 100Wh used (90%), then 200Wh (80%) used etc.
I know this is very simplified and getting the exact voltage is difficult, but you would get at least a rough guess. Showing a 80% charged battery as EMPTY, just because you didn't charge over the threshold??
Or if nothing else you could use predefined discharge curves for li-ion, li-fepo4, li-mn etc and rely on unloaded voltage only (still for a rought guess)