thermo-electric coolers and amps

[AMonger]

I put my thermo-electric cooler in my van. I had it installed in my TTs and STs before. But now I'm doubting that my CV's single battery will survive any period of time with the cooler running. Has anyone else done this? How long does the battery last? This is a large, Coleman cooler, not the small ones seen in truckstops.

 

[chefdennis]

install a battery isolator and a "house bank" of batteries to power accessories, either directly off the batteries for 12 volt or off a inverter for 120 volt items....i use 2 6 volt golf cart batteries and a 3000 watt inverter....

 

[Turtle]

A cranking battery, as you would have on a cargo van, is designed with porous thin lead plates with lots of surface area that allows for putting out large amounts of amps in one whack to start the engine, and is not designed for the long low amp draws of something like a cooler. When you use a cranking battery for something that it is not designed for, like a cooler, the lead plates simply cannot keep up with long relentless current draws and will be depleted quickly, rapidly shortening the life of the battery.

I don't know what kind of Coleman thermoelectric cooler you are talking about, byut the only large ones I know about are the 40 quart PowerChills that can be found at places like Walmart and at many truck stops. It's the kind I used to have. Since a constant 1 amp draw can run a cranking battery down dead overnight, and the power supply for those 40 quart coolers draws a maximum current of 5.25 amps and an average of a little more than 3 amps at 12 volts over the average 8 hour night, there ya go. It's not a problem while the engine is running, but when the engine if off it's only a couple or three amps less than leaving your headlight one, and 2 or 3 times that of leaving an interior dome light one.

Your best bet is to use an auxiliary battery, something like a "marine" hybrid from Walmart of someplace, since those are designed for the long relentless low amp draw of marker lights and trolling motors, the same exact draw of a thermoelectric cooler.

Use a battery isolator to keep the aux battery isolated from the vehicle's system when the key if off while still allowing it to charge when the engine is running. A battery like that will also work for an Espar heater, a laptop and a few florescent or LED lights, as well. And make sure you fuse the battery and all attached 12-volt loads.

 

[AMonger]

I don't know what kind of Coleman thermoelectric cooler you are talking about, byut the only large ones I know about are the 40 quart PowerChills that can be found at places like Walmart and at many truck stops. It's the kind I used to have.

That's the one.

Your best bet is to use an auxiliary battery, something like a "marine" hybrid from Walmart of someplace, since those are designed for the long relentless low amp draw of marker lights and trolling motors, the same exact draw of a thermoelectric cooler.

(sigh) I put the cooler onboard to save money. Things have been so slow, I'm bleeding cash from eating on the road. So in the short term, putting this onboard is going to cost money until the ROI kicks in.

 

[ebsprintin]

I've used the coleman cooler for four years between a TT and van. It ran 24 hours a day in the truck and met my requirements. In the van the starter battery could not do the job. I had it on when running and off when parked, and it only managed to keep the contents damp from condensation. With my aux battery bank I still had troubles keeping the batteries charged. The meter showed that the cooler constantly consumed 4 amp/hrs. I now have an Engel refridgerator that sips power. It draws 3 amp/hrs when the compressor is running then it shuts off until the thermostat requests more power. During this time of year the compressor runs about ten minutes each hour. And it gives me real refridgerator performance.

eb

 

[layoutshooter]

We are looking to put a small, say 2 cubic foot, freezer in the truck. We just have yet to figure out just where to put it.

 

[piper1]

I've used the coleman cooler for four years between a TT and van. It ran 24 hours a day in the truck and met my requirements. In the van the starter battery could not do the job. I had it on when running and off when parked, and it only managed to keep the contents damp from condensation. With my aux battery bank I still had troubles keeping the batteries charged. The meter showed that the cooler constantly consumed 4 amp/hrs. I now have an Engel refridgerator that sips power. It draws 3 amp/hrs when the compressor is running then it shuts off until the thermostat requests more power. During this time of year the compressor runs about ten minutes each hour. And it gives me real refridgerator performance.

eb

I can echo eb's experience. I have had Colemans and Koolatrons and neither would reliably keep things like milk from going bad in any weather. I also found them to be power hogs for what they did. For the last 2 years I have run a Dometic fridge/freezer. Yes it cost a LOT more than a Coleman but it has never let me down performance wise (even if the truck is parked in the sun and is 130 deg inside) and consumes less power. I simply set it for 34 deg and it stays within a 32-35 band. Nice cold milk and orange juice every time and no fear of meat spoiling.

 

[Turtle]

I've got a Microfridge, a 3.46 cu ft refrigerator, a 1.38 cu ft frost-free freezer and a 700W microwave combination. It's gnarly, 108 pounds, 57 inches tall, 19 wide, and 23 deep. Keeps food cold, ice cream and other frozen foods rock solid frozen, and holds enough groceries for a week or 10 days. But it's amp hungry since it's a 120v appliance, so you've gotta have the battery bank to handle it. When it's running it'll pull 10-12 amps, and it runs alot. In the summer it runs probably 16 hours a day, cause it's hot, and in the winter it'll run 16 hours a day 'cause the Espar blows on it. When the weather is just right, it'll run only about 6 or 7 hours a day, tho.

Dometic and Engel are both excellent choices. High dollar, but you do get what you pay for, and in the long run will end up costing less than having to maintain a larger battery bank, unless you're insanely familiar with having to maintain a large battery bank.

 

[layoutshooter]

We are just looking for a freezer, no fridge.

 

[ebsprintin]

Layout,

The engel I have is single compartment with the thermostat going from "cool" all the way down to a freeze setting. I ordered it from Cabella's.

eb

 

[layoutshooter]

Layout,

The engel I have is single compartment with the thermostat going from "cool" all the way down to a freeze setting. I ordered it from Cabella's.

eb

I will look at it. Maybe I can get it somewhere else. I no longer deal with Cabela's since they "stuck it in my ear several years ago when I worked for them. Thanks for the info.

 

[RLENT]

Try Gander Mountain ..... at least they aren't looking to suck on the public teat every time they wanna open up a new store (AFAIK) .....

 

[Turtle]

Amazon's got 'em, too.

 

[AMonger]

I can echo eb's experience. I have had Colemans and Koolatrons and neither would reliably keep things like milk from going bad in any weather...

My experience (at least in TT and STs) has been the reverse. I've had many instances of milk and anything with water or juice in it ftm freezing, even in the summer. But that wasn't in a van, and back then I had the truck's battery bank that would handle the load, so I'm sure it would be different in a CV.

I did plug the cooler in in the van the other night for a few hours, and when I came back to check it, it was cold inside and the van started easily. Of course, that's at night, not with the extra power draw of the thing trying to cool the contents on a hot summer day.

 

[greg334]

The adage a full fridge is a happy fridge means a lot.

Get some ice packs and run the thing when you are driving. Then unplug it for a while when you are sitting.

Engel is the way to go by the way. Some of their dealers had a sale on them - $499 was a good buy - but I think that ended at the start of April.

 

[Moot]

OVM posted this link a few weeks ago. I bought a small Xantrex inverter from them. Check it out for Engel and other brands of 12 volt refrigerators, freezers, coolers and other stuff.

Portable Ice Makers, Travel Coolers & Dishwashers for an RV & Outdoor Lifestyle

 

[ebsprintin]

My experience (at least in TT and STs) has been the reverse. I've had many instances of milk and anything with water or juice in it ftm freezing, even in the summer. But that wasn't in a van, and back then I had the truck's battery bank that would handle the load, so I'm sure it would be different in a CV.

I did plug the cooler in in the van the other night for a few hours, and when I came back to check it, it was cold inside and the van started easily. Of course, that's at night, not with the extra power draw of the thing trying to cool the contents on a hot summer day.

One of the problems of the dielectric cooler is that it only has two settings--plugged in or not. Death Valley summer or North Slope winter the draw is the same. A real refridgerator runs according to a thermostat, so the machine is drawing only the power required to meet a certain temperature.

eb

 

[LDB]

I just ordered this one with the $30 off coupon that ends today and free shipping. Still expensive but seems the best way to go from power consumption etc. standpoint.

FP430 Compact EdgeStar Portable Refrigerator Freezer

 

[Turtle]

What's a dielectric cooler?

Igloo, Coleman and other manufacturers of these thermoelectric coolers will all tell you that they recommend 2-3 hours maximum running off a vehicle starter battery with the vehicle not running. Igloo, Coleman, one of them, makes a portable power pack for picnics and stuff that will power the cooler away from the vehicle, and it's a 17 amp hour unit for about 3 hours of cooling.

Most thermoelectric coolers are designed to cool as much as 40 degrees below ambient temperature. That's fine for when ambient temps are between 68-80 degrees F, which is also the recommended operating temperature for most units. But when the temps get above 80 degrees, or the humidity is above about 60%, the cooling capacity of these coolers drops dramatically.

At one time, way before expediting, I had an Igloo 40-quart thermoelectric cooler that actually had a thermostat on board, and it worked great. It even had a low-voltage cutoff which would cut the power to the cooler when battery voltage dropped below a suer-selectable voltage. You could use it as a cooler or a warmer by switching the orientation of the power plug, just as you can with many of the truck stop coolers, but the neatest thing is that the cooler would cool or heat, automatically, depending the setting of the thermostat, which prevented things from freezing when operating in cooler ambient temperatures. But they apparently no longer make those. The thermostat quit working after about 4 years and no replacement parts were available.

The only thermostatically controlled thermoelectric coolers that I know about are the ones from Koolatron. They're nice, digital thermostats, will heat and cool automatically to achieve desired temperature, but not cheap. The 52-quart P85-PC3 will run you about $390, while the same P85 without the thermostat will only cost you about $150.

Edit: As Leo found out, in the long run, a 2.5 amp EdgeStar becomes far more cost effective than a 4.5 amp thermoelectric cooler. Still, don't run an EdgeStar off a cranking battery for more than a 3 or 4 hours. Get an aux battery for it.

 

[LDB]

I've got a separate "household" battery that's designed for that usage so it should give several hours service. It's on a separator so it can't possibly drain the starting battery. I've got the Onan that will recharge it as needed. Also, since it is a true refrigerator with thermostatic control it doesn't "run" 3 hours to run 3 hours. I'm sure in full summer it will run a lot but don't expect it to run continuously. I hope it was a good decision. Time will tell.