Portable Fridges - Power Source?

[offroad_nomad]

There has been plenty of helpful discussion lately regarding different portable fridges. However, as far as I can tell, not much discussion on how to supply power to the fridges. With warmer weather quickly approaching, my SAR team will be spending weekends in the Shenandoah National Park providing search and rescue services, including medical aid, for the park rangers. We took a 14 yo off one of the mountains with a broken knee this past weekend.

Considering this, a portable fridge sounds like a good investment over standard coolers. So this leads me to my question, how do you power your portable fridges?

• Dual Battery System
• Separate/Dedicated auto battery
• something else I've over looked?

Also, any pics of your power set-up/wiring would be appreciated. Thanks.

 

[elcoyote]

Powering your fridge depends upon many factors. If I am out on a trail run (without my trailer), driving all day and only shutting the engine down for 12-14 hours for an overnight camp, I can run my Engel 45 off of the vehicle starting battery, an Optima red top group 27. The Engel 45 only draws about 1 AH if used on the #1 setting (35-40 degrees). If I am base camping and plan to run my fridge for multiple days without recharging the battery from the alternator, then I will take one of my trailers. We have used the fridge sucessfully for 3 1/2 days on a 105 AH deep cycle battery. Here are the general rules of thumb for deep cyle use:

1-Only count on 80% of the AH rating before the battery dips below 10.5 volts. Many appliances will not operate below that range.

2-It is recommended that you only discharge deep cycle batteries 50% to preserve their life.

I have set up my trailer to run my fridge for indefinite stays in Baja so just in case I decide to not come back, I won't run out of cold beer :beer:
To accomodate this goal I have set up the trailer with two Lifeline AGM batteries rated at 105 AH. This battery bank is charged from the tow vehicle via a 10 gauge wire with a 25 A fuse. When in camp, I disconnect the trailer from the tow vehicle to prevent accidental discharging of the vehicle battery (the vehicle can also be protected with a diode in line). While in camp, I connect an 80 watt solar panel through a charge controller. This makes about 5-6 amps per hour of full sun (normally 5-6 hours at our latitude). This keeps up with consumption and the batteries store the excess for overnight use.

One of these days the fishing is going to be sooooo good, I might just stay :sunflower

Here's a pic of the get up

 

[flyingwil]

As mentioned it is not necessary to have a dual battery set up to run an Engel. However, for extended run times it is recommended.

 

[Hltoppr]

I went ahead and added a second deep cycle marine battery to run my fridge when I installed the fridge. I felt that the main times I'd be using the Engel would be in remote locations, so I wanted to keep my starting battery separate.

That being said, the good quality fridges use a surprisingly low amount of juice. I can run my fridge for 3 days or so on 1 before the battery is out. I make it a habit to turn on the truck at least once per day if we're in "camp/chill out" mode and not driving. 30-45 minutes seems to do the trick.

With a deep cycle marine battery, you wouldn't necessarily need to hook the battery up to your vehicle alternator, just bolt it down somehow in the truck, then use it and recharge it later in the garage, just as if it were used on a trolling motor....

Cheers on your SAR work!
That others may live....

-H- :victory:

 

[Scott Brady]

With the plentiful sunshine in the Southwest, I use a 55ah blue top optima and two 20watt solar panels. As long as the days dont get cloudy, I can run the fridge indefinetaly on that arrangement.

If it does get cloudy, I just start the motor when the aux. battery drops below 11.5 volts.

 

[offroad_nomad]

Thanks for all the suggestions, these are all very helpful.

Scott,
Is there any hardware installed between the solar panels and your battery to aid in recharging or trickle-charging it? That might be a nice option since I don't think I'm going to install a dual battery system up front. I guess I could also attach an inverter to this separate battery as well if I used the solar panels for recharging. Thanks.

With the plentiful sunshine in the Southwest, I use a 55ah blue top optima and two 20watt solar panels. As long as the days dont get cloudy, I can run the fridge indefinetaly on that arrangement.

 

[Mlachica]

dual batteries

I'm using an odyssey 1700mjt as my aux battery to power the fridge and other equipment while the 1200mjt starts my truck.