Electric Cooler Problems

Hello: So the last several times I've taken the teardrop out the electric cooler conks out after 10-12 hours on dc power even if its plugged into the galley outlet and the car is running. To test it I put the cooler in my car and plugged it into the power outlet and it works fine. The AC (alternating current) works fine as well. The voltage meter shows plenty of juice on board, and if I plug in my cell phone charger is also shows power coming through. So something is kicking the power off of the Dometic CF-35 within the teardrop electric systems. Anyone had this problem? Thanks.

 

Are you running the cooler with the galley lid closed? The cooler depends on relatively cool air blowing over its condenser. In the small enclosed galley space the air heats up and the cooler kicks off with a high ambient temperature error.

 

If the Dometic has shut down and you briefly start the tow vehicle to provide charging to the battery, it MAY still be possible that the battery charge has not increased enough for the Dometic to run (at least not for long). The manual will state at what voltage the Dometic will shut off. Charging via the alternator should increase the battery voltage, but once the alternator is shut off you will see the voltage will drop fairly quickly. My uninformed suspicion would be that you would need a fair amount of alternator charging before the battery voltage would be high enough for the Dometic not to draw it down below the minimum required, but that is purely a guess. (Cary has told me that about an hour of alternator charging should be sufficient to top off the battery, though I presume that is at traveling speed, not at engine idle speed.)

The difference in your two scenarios is that, in the tow vehicle you have a fully charged battery; in the camper you have a depleted battery. I think that explains your observations. The charge from the alternator is immaterial until it has had sufficient time to recharge the camper battery.

The manual will also explain that there is a hi/lo (or perhaps hi/med/lo) setting that dictates how the Dometic responds to a low battery condition. You should read that to make certain that you choose the setting that is most appropriate to the sort of scenarios that you are experiencing.

 

Our new approach is to not plug the Dometic into the TD while we are driving. We will plug the Dometic into the car/TV while driving, and let the car charge the TD battery without the Dometic getting in the way. The TD battery charges better if the Dometic isn't plugged in to the TD while driving, from what I have heard and now from what I have experienced.

Also, when the TD galley hatch is closed, it gets very hot in there. So the Dometic is working extra hard and that has to be drawing extra hard on the battery charging system.

If you do adopt the system of having the Dometic plugged in to the car, don't forget to unplug the Dometic if you leave the car for a while, so it doesn't kill the car battery.
-Al

 

We keep the Dometic inside the tow vehicle, and keep our food supplies in another cooler in the Teardrop. The cooler in the Teardrop is nothing more than a storage container. By keeping the Dometic in the tow vehicle, snacks and drinks are readily available. This has worked well for us.

 

We likewise do not put the Dometic in the galley. We use the Coleman for dry food storage in the galley and the Dometic goes in the teardrop and plug into DC outlet. Have had no problem with over heating.of the Dometic or charging issues with the teardrop battery. We have left the dometic in trailer for up to 8 hrs. parked without the tow vehicle running. The battery is low, but charges quickly in an hour or so. Like this arrangement so when we stop for an extended period we don't have to unplug the Dometic if in the tow vehicle. When the Dometic is in the trailer I will typically pack some things close to it to stabilize it in case of a quick stop, taking care not to block air vents on the fridge. R

 

My understanding is that leaving the Dometic plugged in to the TD battery while the TD battery is charging from the car, has a negative effect on the TD battery. You are dimishing the capacity of the TD battery, is my understanding. Perhaps this doesn't happen if you have a tow vehicle that is more than adequate for charging the TD battery, but I'm not sure. From talking to folks and doing research, this is a bad thing for your TD battery.

But I agree that the galley is the worst place for the Dometic, while driving (and even when not driving).

I would also be worried that the Dometic will bounce around eventually damage a cabinet or more, inside the trailer.

I believe the better approach is to have the Dometic IN the tow vehicle, but this does pose issues when the tow vehicle is off, as the Dometic could quickly drain the car battery.

(but I've been wrong before!)

-Al

 

Thanks for the info on charging, I will do a bit more.research on that. Since I am not an electrical engineer do you know if the same holds true if charging the TD battery from a solar panel and running the Domectic also has an adverse effect on
the TD battery?

 

I believe it is not a negative impact on the battery that is the problem when the Dometic is running off of battery power. It is the negative impact on the battery tender (which uses AC power to trickle charge the battery) when the camper is on AC power, but still running the Dometic off of DC. The draw from the Dometic is sufficient that the battery tender never thinks it can get the battery fully charged. As a result, it can run for hours at a time. If it runs for about 10 hours nonstop it will overheat and get fried (this has happened to us, but not due to the Dometic). The solution is to run the Dometic on AC whenever the camper is on shore power.

Solar is not a problem, as the solar charges the battery directly. It may even help prevent overheating the battery tender (if you were to leave the Dometic on DC power while it is at work), since it would be supplying some of the power for the Dometic load.

 

Yep agreed. We do not run the Dometic off the battery (DC) when on shore power (AC). Only use DC when on the road or solar,,,,R

 

Thanks for all the great input on this problem and tips that I'll use going forward with the Dometic. Looks like the solution is in changing the battery monitor on the Dometic from high to medium, pursuant to Cary and other commentators' advice.
ps...just got back from Death Valley and it's a great time to go!

 

I don't know the answer to this question, so I defer to Steve & Alea (Inn42). I think the diminished battery capacity issue is related to the battery abuse that is caused by charging the battery from the car while the Dometic is drawing a heavy load. I don't think it's only a battery tender issue. Even if the tender is fried, replacing the tender will not fix the battery capacity issue. Once you've abused the battery, you've abused the battery. You can't recover that diminished capacity.

(and this may only be an issue with an AGM battery)

(again, I could be wrong)

 

Changing the setting on the Dometic is not the only action you need to take to preserve your battery capacity. If the Dometic is running off the TD battery while the TD is being charged from the tow vehicle, you will continually reduce your TD battery capacity, afaik. (just as you will if the Dometic is plugged in to the TD's 12V/DC source(battery) while the TD is plugged in to shore power). Solution: The Dometic should not be plugged in to TD DC while the TD is charging from the TV or from shore power, afaik.

(but you do also want to use the right setting on the Dometic, for when it is plugged in to DC)

ps We are headed to Carrizo Plain in two weeks - am hoping the wildflowers haven't burned out by then!! I bet Death Valley was incredible!!

-Al

 

You are correct about loss of battery capacity becoming permanent. I don't know that, aside from batteries just generally losing capacity due to age and degree of use, there is conclusive proof about the Dometic greatly accelerating the long term depletion of the battery. Current speculation is that this MAY be more of an issue with newer, more efficient vehicles, which are equipped with alternators that produce a lower charging voltage than older vehicles (thus they don't top of the AGM battery as well as happens by the battery tender while on shore power). But at this point it is far from proven - more just something else to consider for those having specific problems related to the battery and/or Dometic.

Hopefully early next week we will have installed our own personal approach to addressing these issues. Once that happens we will be camping around the fringes of the Treasure Valley (Boise, ID to Ontario, OR) for about a month or so, documenting various aspects of this issue. I doubt if what we learn will end speculation, but hopefully it will add some useful facts and anecdotal evidence for further consideration.

 

I travel with the dometic in the Galley and have had no issues. However, my TV is a BMW X 5 which comes equipped with an AGM battery so my charging system must be up to the task

I did adjust the battery monitor on the Dometic down after about three days in Death Valley one time. I had solar but noticed that the Dometic was cycling on and off about every three seconds in the middle of the night. Our guess was that my battery had enough juice for the fridge to run but that the start-up may draw more amps than when it is up and running causing the sensor to shut things down. On/off on/off on/off

After I set the monitor to a lower setting the Dometic ran fine through the night and the solar kept us going the rest of the trip

 

I travel with the Dometic on 12 volt in the galley, no issues that I know of. 2014 Ram 1500

 

Having an issue with my Dometic CF 35. The panel has gone all weird. Cant turn the cooler off or on. Some lights are lit up but not all. Trying to adjust the temp does not seem to work. I can feel the compressor turning on but I have no confidence in the temperature setting. The panel got wet but this cooler should be able to handle some water on the screen. Not sure if it's just the panel or the mother board. Anyone know how to test these and the best place to buy replacement boards?

 

Sounds like the PCB that runs the fridge has a problem. I had a similar problem and managed to find a replacement board for the Dometic online somewhere and put it in. It worked for a period but the fridge failed again. I guess mine was a lemon. I got tired of getting stuck with a dead fridge and took some one else's advice from the forum and got a Snomaster fridge. It's been great, a little bulkier to lug around but more capacity also and a quality machine that I've used for several years now.

 

Here is what the screen looks like. It’s cooling but I have no control over temperature. In fact it’s freezing water. But the display doesn’t change no matter what buttons I press. All locked up. I guess we are eating ice cream for Sunday through Wednesday next week!