I am trying to set up a solar generator to run two dorm fridges in the back of my truck. This weekend I wanted to see how many days the fridges would run on my 230 AH battery with no charging. They only draw a total of 1 KWH for the two. Anyways I had then run fri afternoon, all day sat and then sun I checked the app and it said 67% life in the battery. I then was gone for the day. When Igot home my inverter alarm was going off saying "Low voltage". The % on the app was still reading I had 65% more battery live but the volts was low. IS this common for the % (the biggest number on the app) to be that far off. In my mind I would have expected it to be at 10% or lower if my inverter cant pull enough