esp32 has a deep sleep mode, easy to use, works on my linux since it uses the arduino ide, but i didn't find a nice board, so a lot of soldering....
my victron solar charger also has that smart output, but my inverter pulls to much current for it...
if the battery gets to low the inverter switches off, but it makes that neverending beep sound, hope the new one is not so loud..
i really would like to be able to read my voltage over the internet, to get an alarm on the cellphone...
RE: Cold Nights