Run fridge on standard batteries

[Joshp82]

Hi everyone. Just wondering how my ute will go running a fridge for a day on the standard D22 batteries? I'm going away for 1 night. Will my batteries die on me? It's a mobicool 40L fridge. It says 4A draw on the back.
Thanks
Josh

 

[LLadnar]

I ran my 80ltr waeco of a single battery for two days in my D40 and started no prob. D40 battery is a little bigger but you should be good.

 

[terryc]

My 2c is that it should be okay, but I would not do it too often as car batteries are designed to be instantly recharged.

Is the 4A continuous? Then definitely not.
If 4A is the maximum current draw on maximum cooling, then you might run into trouble in summer if the fridge is working hard. just hope for cold nights :bg.

 

[Joshp82]

Might just pack the esky with ice instead. I'm not sure if the draw is constant or max. Will wait till I hook up a deep cycle before I take the fridge.

 

[Mairs]

If you're going to run off the SLI batt then I would have a mini jump starter on hand. Best $250 we've ever spent for the piece of mind. We've flattened our D40 batt overnight with our 110lt Waeco in the CT which has dual batts. That's a lot bigger than yours I know, but amazing how much juice they need. You might get away with it for a night

 

[Old.Tony]

I have a 32L Tropicool that draws 4A, it uses a Peltier-effect cooler. Cools to about 30C below ambient, it says.

It's only useful in winter, summer is far too hot (45C minus 30C = 15C for the milk, I mean it's yoghurt now). It draws 4A under load and runs about half the time (on a normal summer day). On a night like tonight where the BOM predicts an overnight low for Brisbane of 11-12C you should find its usage a fair bit lower. Let's just say, for argument's sake, that it will cycle ON for 30% of the time.

If you're stopped from 6pm to 8am = 14 hours = 4.6 hours of operation = 18 amp hours.

Your battery should be around 55Ah with 75% of its capacity because it's alternator-charged = 41Ah so using the fridge should lower it to 23Ah or just under half its remaining capacity. That's fine.

Don't use the radio or lights unless you want to start the engine for about 15-30 minutes to top the battery up - you could flatten it, or cause damage to it.