Hi. Thanks for your reply. I just installed the fw 72.75 and MCU 12.28. Tomorrow I start with the MPPT logic tests. The SOC is correctly displayed in Watchpower. I use the Voltronic protocol on the JK and the LIB protocol on the inverter. NB you need to use the RS485 cable that is supplied with the inverter that has a particular pinout (pin 1 battery side connected to pin 3 inverter side and pin 2 battery side connected to pin 5 inverter side). Thanks again. Ps do you know what improvement the fw MCU 12.28 introduced? Thanks.