Running a fridge on 24v (2 Viewers)

[mulebarn]

Hey Legends,

For those with 24v systems, how have you solved running a fridge on trips? Dual battery systems don’t seem possible, and running an extra 12v alternator and a 12v battery is no small undertaking either.

My ARB fridge monitors the battery and has automatic shutoff, but I don’t know if I’d trust that when I only have the main battery to rely on.

Thanks,
Gino

 

[Loober]

I built a 12v switched and constant fuse panels to be used for all the 12v accessories including the fridge. The 12v constant feed to the fuse panel comes from the pos terminal of the forward battery. The switched power source is activated by a 24v relay thats triggered by a 24v switched power source, it switches a 12v feed from the constant panel to the switch panel. So yes the 12v is coming from one of the batteries, therefore discharging it faster then the other battery, to take care of that, I installed a battery equalizer that keeps both batteries even. I've had this setup for 3 years, although I don;t have any major 12v accessories like a winch, I run the fridge, gauges, 12v usb ports and have not noticed any ill effects on the battery. The equalizer is a must I use the Vann guard one, I periodically check voltage on each battery and its always within .1 volts of each other.

 

[GTSSportCoupe]

There are also some pretty high power and highly efficient DC DC converter's available out there these days. 24V->12V at high current.

 

[umpqua]

My truck is 24v. I'm running the 12v Engel off of a 12v Lithium which is charged by a 12v under the hood Kubota tractor alternator. Solar when parked. Basically all of the other accessories other than the winch are 12v as well. A bit of a PIA to get it all set up but I never worry about the truck starting.

 

[roscoFJ73]

My ARB fridge monitors the battery and has automatic shutoff, but I don’t know if I’d trust that

You will either have to trust it or get another cut off switch fitted. But a 2nd battery is the best way, preferably a deep cycle.

 

[mulebarn]

There are also some pretty high power and highly efficient DC DC converter's available out there these days. 24V->12V at high current.

I have three in my truck already. The ARB fridge does 12 or 24v, but what I’m trying to do is run the fridge, preferably not off the starter batteries.

 

[mulebarn]

My truck is 24v. I'm running the 12v Engel off of a 12v Lithium which is charged by a 12v under the hood Kubota tractor alternator. Solar when parked. Basically all of the other accessories other than the winch are 12v as well. A bit of a PIA to get it all set up but I never worry about the truck starting.

Did you do the work yourself? I’m also in Portland, and would love to take a look if possible!

 

[Loober]

Here is another option that the Vann guard equilizer provides that I may do in the future. It can charge auxiliary 12v batteries without the need of a separate 12v alternator. One thing I am not sure of is how does it know if the main batteries are healthy enough to charge the aux, maybe some kind of smart solenoid can be used.

 

[clintnz]

There are also some pretty high power and highly efficient DC DC converter's available out there these days. 24V->12V at high current.

This. I have 12V so I just use a smart battery isolator to switch charge to my 2nd 12V battery that runs the fridge, but with a 24V truck it is just a matter of spending a few bucks more & putting a DC/DC converter with an isolation function in place of the smart isolator to feed a 12V battery. Most also have a solar panel input. Something like this.

Or go Redarc if you have $$$ to burn.

Also remember to put the DC/DC converter right at the 12V battery, as you get less voltage drop in the 24V leg of the circuit.

Cheers
Clint

 

[Andrewdm]

I used an ArkPak to run my fridge. You can pull it out when not needed and recharge the battery using the ac adapter. It was a simple solution for me as I needed to use the fridge in multiple vehicles.

-Andrew

 

[umpqua]

Did you do the work yourself? I’m also in Portland, and would love to take a look if possible!

Do the work myself? No way that I have the skills. I'm fortunate to know a guy locally that does great mechanical work. I'm happy for you to see the truck so just let me know.

The discussion on the alternator starts around #62 in this thread. Builds - Portland Troopy Build

 

[mulebarn]

Do the work myself? No way that I have the skills. I'm fortunate to know a guy locally that does great mechanical work. I'm happy for you to see the truck so just let me know.

The discussion on the alternator starts around #62 in this thread. Builds - Portland Troopy Build

Ah, you’re the guy Josh was telling me about. Haha!

 

[umpqua]

Depends on what he was telling you.

 

[cruiserdan]

Another way to approach it would be to run the fridge off of the vehicle's 24volt bank and carry a couple 12 volt lithium booster packs as a backup to jump the truck if you pull the batteries down too far.

 

[mulebarn]

I happened to speak with someone at Zamp solar today, and he told me that they worked with Dometic on some product tests with the Dometic 40 Ah Lithium portable battery. He said (as a third party) that the Dometic battery will run a fridge for a weekend with no charge, but with a solar panel it’ll go Indefinitely. The battery also charges via cigarette socket and regular home socket as well. So it’s similar to the ArkPak mentioned above, but less than half the size. I have a solar panel for use with our Sprinter van, so I may go this route as a first test for trips of 2-5 days, and hopefully can just get double duty out of the panel. Seems dirt simple, and easy to take out of the 73.

Thanks everyone for all the ideas. I love this group!

 

[fireball]

Why wouldn’t you just run the fridge off 24v?

It’s more efficient that way. The low voltage cutoff on arb fridges works very well ( at least does so on mine) and a solar panel is way cheaper and easier than complicated battery solutions.

 

[mulebarn]

Why wouldn’t you just run the fridge off 24v?

It’s more efficient that way. The low voltage cutoff on arb fridges works very well ( at least does so on mine) and a solar panel is way cheaper and easier than complicated battery solutions.

General practice is to not cycle your starting batteries. The solution I’m going with is simple, reliable, and portable. (See my last post)

 

[hoser]

Or something like this.... FuelZero 24v 25AH Deep Cycle LIFEPO4 Battery

 

[mulebarn]

Or something like this.... FuelZero 24v 25AH Deep Cycle LIFEPO4 Battery

I went with the Dometic PLB40, which is Lithium Iron Phosphate. You get far more charge from that than Lithium Ion.

 

[cruiserdan]

I went with the Dometic PLB40, which is Lithium Iron Phosphate. You get far more charge from that than Lithium Ion.

At around 800 bucks it seems to be suited for well-heeled clients. It is certainly out of my reach.