I am borrowing a Snowmaster dual (28 & 24l iters I think) fridge/freezer from a friend. Yesterday afternoon I connected it to the 2nd battery in my Ranger XL Plus. During the 20min or so trip back home, the temperature of the empty fridge dropped from 23deg to 4deg. I left it overnight just connected to the 2nd battery. I wanted to see if it will run through the night. When I checked this morning, the fridge was not running and the temperature was at 20deg. The battery voltage was at 12.6V as indicated on both the fridge display as well as the battery monitor I have on the battery.

When I checked this morning, I saw that the cut out voltage can be set to anything between 10V and 11.5V. I have now set it to 10V, but cannot remember what it was set to. But be that as it may, it should have only cut out at 11.5V. Any ideas why it would have cut out at 12.6V or higher? I started the bakkie and after a while the "solenoid" kicked in to start charging the 2nd battery. The fridge then also started running again.

Thanks in advance.