Very nice project.
Im interested in building one just like, only in my case there are 3 loads, and ill measure consumption on each load and also the on-grid and off-grid PV production.
The main rule is that if the battery is under rest voltage and PV production is less than total consumption one of the load will be disconnected to even the odds, and some other rules that are secondary.
Can you share your drawings and how did you made an accurate reading of the battery voltage ?
Thank`s !