I'm an early riser, I usually take my voltage reading first thing in the morning, before I switch anything ON and before my tiny solar
panels have put any charge voltage on the battery
. If I can get the battery
charge status within about 10% that's more than good enough for my purposes. My camper is 100% LED and we use the lights
conservatively, the big power hog is the furnace
, we can camp multiple days on a single Gr27 battery
. If it gets too low, I can still back up the truck, plug the pigtail and let it idle half an hour or more.