12 v Cooler Electrical Questions From A Driver

I have a 2017 Volvo day cab and I transport cars on an 11 car stinger. My issue is that although I stay in hotels, I need to keep a cooler in my truck and run it overnight without drawing down the batteries and have a starting problem.

I have a 40 quart Coleman thermoelectric cooler. In the beginning I had it plugged into a cigarette lighter which I believe is a kluge from yesteryear that really doesn't live up to the task when it comes to coolers. The plug kept getting hot and blowing fuses every so often in the truck. So now I've had the shop hook a direct line up to the truck with a 20 Amp fuse. (Somewhere under the hood) They told me that the cooler draws 7 amps.

When I got away with running it through the cigarette lighter I was able to keep it running for over a day at home without having a starting problem. Coolers that go inside a vehicle are labeled 12-volt coolers. When I shut down my truck and while it is running it reads 13.5v on the instrument panel. Truck is also equipped with three batteries. During the cooler season I am able to turn it off overnight and not have any troubles.

So my questions are,

#1 Am I actually running off of 12volts or am I running off of more than 13 volts?

#2 Should my cooler be drawing that much amperage?

#3 Do any of you have any suggestions on how to best remedy this issue for summer time use?

 

Go to the plastic container section at Walmart/Family Dollar etc and get a wide mouthed container and fill it with ice and put it in your cooler. It will keep your food cold in a hot truck.

 

Look at Alpicool. Legit cooler, fridge. Not thermoelectric. It can heat, or freeze to like -4. Mine holds about twelve bottles of water, and the truck starts fine after sitting four or five days. Plugs into the cigarette lighter.

 

All I know about thermoelectric coolers is that they are junk. Get on Amazon and get yourself one of the real DC fridges that are available nowadays. All sizes and types. Names like IceCo and Alpicool. They are all cheaper knock offs of the high dollar camping DC chest fridges and they are working really well for people. Great deals too.

A DC fridge should draw no more than an average of about 4 amps for the smaller fridges. If your 3 batteries in your truck won't run that overnight then you've got some charging system/wiring issues.

 

Looks like we're typing at the same time GpD.

 

Great minds think alike.

 

If you buy a compressor fridge / freezer that runs on 12 volts it also comes with 120-volt plug you can just take it in the hotel room with you and plug it in

I've got two in my truck that I got on Amazon Alpicool (cheap) and Dometic (expensive).

 

12 volts is the same as 13 volts. Most vehicles run somewhere between 13.6 and 14.2 volts. Batteries will show a higher voltage when truck is first shut off, but will settle under 12.6 after a short while.
Then battery voltage will deteriorate overnight with a load on them. When it gets much under 12.0 then you can start to see starting issues.
Three batteries isn’t enough reserve capacity, add a fourth battery next time you change them out.

 

A bag of ice in the electric cooler I bought 15 years ago, never plug it in, keeps everything cold as can be for 2 days in summer, 3 even 4 in winter.