Dead batteries after less then 10 hours sitting

the Alternator makes the power to charge the batteries and runs all electrical power. If Your alternator isn't running at full power it won't charge the batteries fully and will slowly discharge them over time. I would still have every battery checked and replace the ones that are bad. This test is to see if the alternator is bad or going bad (ground-out) which will kill batteries and can/will burn out a VCS (Vehicle computer system)

 

Those 12 volts coolers are tough on batteries.

 

What about a real refrigerator?

 

I would check to see the capacity of the batteries. Many companies and O/O buy the cheapest batteries they can get to fill the hole. That does not mean they can hold a charge after being discharged for a long period of time. But with winter coming on, you need a battery that will hold a charge and deliver enough current.

You don't want to get stranded in N Dakota in a blizzard wearing these pip squeak batteries that you might get a way with in S. Texas.

 

I never had problems with a fridge. Only had 2 trucks with a inverter with a fridge plugged in. The coolers however eat up batteries. I would unplug my cooler when I got home.

 

Sounds like you need batteries. A simple specific gravity test will tell you what shape they're in. However, after three years? chances are they're weak. You might have a dead cell or two and they will discharge the other cells.

 

My KW battery holder was broken also. I used a nylon tie down strap around the batteries, and not the whole assembly, to keep the batteries tightly together. I used this type because the pull type has a smaller head, so is not likely to beat a hole in the battery. A piece of mudflap between the battery and the strap head will isolate the battery from the metal head. My batteries never moved. You can still use the bungee to keep the plastic frame from coming apart.

 

I unplug frig when I go home. But if I'm staying in a hotel, I'll let it run. If I don't run APU, it will run batteries down in about 12 hours depending on the weather.

 

I just turned my inverter switch off when I got home. Open the door on the fridge.

 

That is important especially in the Summer.