I've read the few topics on workarounds, but I'd like to explore the possibility of tracking three phase charging properly and accurately.
I'm OK with doing any hardware changes to the PCB design and using the extra unused analog pins on the arduino. My challenge is how to make the firmware changes.
So conceptually, I think it's just a case of tracking three sets of current usage (through three independent current transformers), then calculating the sum of all of them and using this to derive kWh, etc.
The benefit of doing it this way is it's fully compatible and "automatic" whether charging single phase or three phase. L1+L2+L3 will always reflect true consumption, whether single phase or three phse charging - in the case of single phase, then L2 = L3 = 0amps.
How feasible do you think this is?