Simplest truck bed fridge setup?

[SanJuan]

What would be the simplest setup to accomplish the following?

• ARB or similar 12v fridge mounted in truck bed
• Would want power source to be charged by truck alternator when driving - bed not currently wired for AC or DC
• Have room to mount a solar panel to load bars on roof top tent

 

[llamalander]

Get a beer and read this... or at least the first few posts

How to make a cheap isolated dual-battery setup for $50

So there are a lot of kits you can buy to have truly isolated dual-battery setups. Those are VERY NICE kits. They are also very expensive. I try and replicate those kits without spending as much money, while still having a similar level of quality and/or reliability. There are constantly...

forum.expeditionportal.com

Put the fridge in your bed, hook it up to a deep-cycle/ lithium battery next to it & run some heavy cables under the cab to the starter battery.

 

[Dave in AZ]

Fridge at 34f uses around 60w an hour on average I'd guess. So for 12 hrs you need 720 watthours of power, so with usable 85%, you need an 850wh battery.

Simplest is to just buy a solar generator like 1000w, and run the dc charge cord up to your 100w cigarette lighter. Mine on Tacoma is ignition switched, so start battery is safe from drain. Fridge will run off alternator while driving, solar gen while parked.


But the post above with 2nd battery and bigger isolated alternator charging is almost as easy. But yeah... buy 850wh for each 12 hrs of run, plug into 12v.

Heck, my solar gen has a 100w usb c input too, if I plug both into car I get 200w charge for 2 wee pre-installed ports.

Run solar into it too as desired, it is all ready to go.

 

[burleyman]

What has already been said.

Do you have a trailer plug? I installed a length of 16 awg lamp cord to the always hot 12v terminals from the trailer plug to the fridge. Silverado. There is sufficient gap to close the tailgate. I installed Anderson style connectors on the fridge.

My fridge draws 4-5 amps when running. No problem overnight. I experimented twice leaving it running until a low voltage fridge shutdown. Truck still cranked. Lithium jump packs are wonderful.

The homemade jumper will also provide some slower aux battery charging while driving. I have a 30ah lifepo4 battery in bed near fridge. If the alternator voltage is in the mid to high 14 volts range, the battery will fully charge while driving. It just takes a little longer than larger wire.

 

[SanJuan]

Thanks for the info everyone. Some good, simple options to consider.

 

[(none)]

How long are you camping for? If you drive the truck every day or even every other day, just wire it to the starter battery. I toss my fridge in the back of my car, it's wired the same in the truck. I don't sit for days at a time when on the road, no issues.

I have another battery, dc to dc charger, etc for the truck, but haven't found a reason to install them yet.

 

[CMARJEEP]

Fridge at 34f uses around 60w an hour on average I'd guess. So for 12 hrs you need 720 watthours of power, so with usable 85%, you need an 850wh battery.

Simplest is to just buy a solar generator like 1000w, and run the dc charge cord up to your 100w cigarette lighter. Mine on Tacoma is ignition switched, so start battery is safe from drain. Fridge will run off alternator while driving, solar gen while parked.


But the post above with 2nd battery and bigger isolated alternator charging is almost as easy. But yeah... buy 850wh for each 12 hrs of run, plug into 12v.

Heck, my solar gen has a 100w usb c input too, if I plug both into car I get 200w charge for 2 wee pre-installed ports.

Run solar into it too as desired, it is all ready to go.

What kind of fridge and how did you get those numbers? They seem way too high. I’ve had a couple different fridges and both have pulled consistently right around 15ah a day or 180wh. This is measured with a Victron Smart Shunt and I keep my fridge set at 36 degrees.

I have a custom built battery box with a 50ah Lifepo4 battery and it will typically run my fridge plus charging accessories for 3 days with no solar. With my 150w panel it will keep it charged up indefinitely.

 

[Dave in AZ]

What kind of fridge and how did you get those numbers? They seem way too high. I’ve had a couple different fridges and both have pulled consistently right around 15ah a day or 180wh. This is measured with a Victron Smart Shunt and I keep my fridge set at 36 degrees.

I have a custom built battery box with a 50ah Lifepo4 battery and it will typically run my fridge plus charging accessories for 3 days with no solar. With my 150w panel it will keep it charged up indefinitely.

Sounds like you are getting some great numbers on your fridge, congrats!

OP said he was getting an ARB. Most of them are 60 qts or larger. All the fridge tests I see online, where guy actually hooks up a watt meter and power station, and video tests them, give 35w to 60 w when cooling, then 13 to 30 holding if door isn't opened. Assume the worst when planning capacity, fridge opened and closed, so running hard, lowish temp, large fridge. I live in Phoenix, this Aug we had 3 weeks of >115f, and it was hotter than that in my truck bed! Power usage higher in that kind of situation.

I watch dc fridge reviews on Hobotech, ReeWrayOutdoors, and Jasoneid.

Also, I said 34f, not the 36f you referenced, nor 37.4 ARB tests. Which will draw more power.

Pick whatever power draw you want, but IMO it is better to not assume super efficiency and the best of all worlds when answering internet questions... best to be conservative in assumptions and calcs, so you don't set folks up for failure. Large inefficient fridge, constant use, Phx summer--until told otherwise I assume worst case.

 

[workerdrone]

How long will you be out at a time? Simplest would just be strap the fridge down in the bed with a good size Lithium battery and no charging at all. Just size the battery big enough and charge when you get to an outlet.

IF you're only out for a few days at a time....