Acutemp AX56L battery charging help

[Backwoods deuce]

Hello all, recently I picked up a Acutemp fridge and got the refrigerant refilled and installed rank new batteries. This issue I am having is that the batteries are either rapidly discharging, or are not fully charging. I can leave the unit plugged into 110 power for 24hrs and the display says 100% with 14.5v but never switches to float. So I’ve tried running the unit on batteries in cool mode to make sure it’s operating properly and after 10-11 hours I’m at 10% battery at 11.5v per the display. If I’m not mistaken it’s supposed to support cool mode for at least 24 hours? Called Csafe and they said they couldn’t help me since I’m not military. Anyone have some insight to this issue?