Finally found the time to make some progress. While I was gone for a while I have acquired ESP8266 modules so instead of the NRF24l01+ I'll be using the ESP8266 for wireless communication. Change of component caused a small change in schematic.

Progress on the software part is mostly writing the control of the system. The menu is finished and the ESP8266 is configurable with the menu.

Next up is the PWM out for the charger and the voltage measurement.