12V Fridge wired direct to battery on the truck?

3 probably reasons for this. What gauge wire did you use to run the power, how long did you run it, and how did you attach it? The thinner the wire the more resistance it has leading to lower voltage at the fridge. Same with the length. You really want to consult an ampacity chart for that. Terminal connections are notorious for being loose in a few ways. The crimp could be wonky or loose or the terminal itself could be making bad contact due to contamination of any number of surfaces where you connected it. Make sure surfaces are clean, and you didn't stack too many things on the terminal.

For an ampacity chart refer to the power draw sticker on the fridge. It'll likely have watts which gets amps by dividing by the voltage. Fully charged voltage for a battery is around 13.6V so you would take, lets say 200W, and divide 200/13.6=14.7A which can be a significant amount of current if that were the power draw.

 

I gave up on 12 volt fridges years ago I’ve been using $100 Walmart bar fridges . I typically get 5 years out of them.. I’m on my second one in 12 year span .. I can leave it on all the time unless I’m home for more than 2/3 days that is ..my factory 12 volts killed batteries in 36 hrs easily.. note I run the fridge on the extra Parksmart batteries.. Is there any chance your post sees higher voltage/amps with truck running?

 

I wonder if the difference between 12v battery output and the typical 14v alternator output might be causing this?

 

The fridge is drawing to much current, I also use a 110 volt and just run it off the comverter, changed years ago, the connectors on the 12 volt fridges used to overheat and melt.

 

Its a current problem not a voltage problem. He could run them stright to the batteries, batteries not switches. The trucks disconnect does not normally handle the full current, but switches a relay, typically.

 

12v coolers don't work as good as 110v coolers.

 

Dont you need an inline fuse in the wire between appliance and battery ?

 

boats especially sailboats run a 12v fridge freezer cool plate that can last decades saltwater environment at that .