ARB Fridge/Freezer Performance Question

Greetings,

I have a 50 qt. (47 liter) ARB Fridge/Freezer which rides in the bed of my '13 Tacoma DCSB. I had the local Leer cap dealer install a triple 12v outlet (a Leer accessory kit) in the rear passenger side corner of my cap to plug the fridge into. This outlet is wired directly to the battery, and the wire looks to be about 16 or 18 gauge. I should add that the truck is 10 months old, has under 2500 miles on it and has the original battery.

I went through a process of setting up and testing the the fridge with the truck in the garage, and it ran 24 hours before the built-in battery protection circuit, set at medium (11.4v cutoff) activated and shut the fridge down.

So, this past weekend, I took the truck out with all of my expedition gear on board, including the fridge. We drove for about four hours at low-moderate off-road speed, then onto the highway for an hour to an hour and a half to home.

Upon arrival at home, I saw that the fridge's battery protection "check" light was illuminated. This indicates that the battery charge had dropped to, at most, 11.4 volts and the protection circuit had done it's job and shut off the fridge.

This puzzles me because we were running the vehicle at highway speed for 60-90 minutes. Wouldn't the alternator be busy maintaining the battery's charge level, regardless of the 5.1 amp draw from the fridge?

So if the fridge draws 5.1 amps when running on a 12 volt supply, I wonder whether the power wire needs to be larger...say 10 or 12 gauge?

Conversely, if plugged in to 110v, the draw is only .75 amps. The Tacoma's 110v outlet is right there in the same corner of the bed. I wonder whether that would be a better power source when under way, then switch to 12v when camped overnight?

Thanks for any help you may be able to offer!

 

I have done a bit more research online, consulting the chart of American Wire Gauge (AWG) and rated Ampacities, and the data indicates the following:

An 18 gauge wire is rated at a maximum of 2.3 amps for power transmission, whereas a 10 gauge wire is rated at 15 amps. The chart also indicates that a 10 gauge copper wire connected to a 12 vdc source will see a voltage drop of 1.75% over a 20' run.

Ok...on to power draw -

The manual states this under "rated current": 12 VDC - 5.1A.
The product description info at ARB's site states this: Average DC power consumption: 0.7 to 2.3 amp hr.

I am not certain what to make of all of that. So which is it...5.1A or 0.7A - 2.3A? I must be misinterpreting the terminology.

If the ARB's amperage draw is 5.1A when connected to 12 vdc as the manual suggests, then the 18 gauge wire (rated 2.3A) installed by the topper company is grossly undersized for the task. If, on the other hand, it is 0.7A - 2.3A, then why am I having any issues at all?

 

If it were me, I would use wire that would handle the max 5.1 amps. I would err on the overkill side when it comes to electrical. Having a little extra capacity would be safer and more reliable.

I don't think your alternator is the issue yet. If you have the option to use the AC, provided it meets the power requirements, i would do that if it draws less current. May be easier on the alternator during driving. DC while camping would be normal, but beware of draining your battery. (Like I had to tell you that.)

 

Problem solved. Ran 10AWG PowerWerx Zip Cord power and ground from battery to outlet in bed. Monitoring voltage and it never drops below 13.5 vdc.

 

Sweet.