Wednesday, March 29, 2023


My Dometic fridge won’t get below 50 degrees. Should I get a lithium battery?

Dear Dave, 
I have the new Dometic 4101 refrigerator that I really am extremely disappointed with. Unfortunately, I am stuck with it as it seems to have poor performance in Texas heat and humidity. Perhaps it could be low voltage, but I am getting 12.4 and reading 8 amps in performance mode. The other settings are worthless as the temperature stays in 50 degrees range both top and bottom with those settings. I am at my wit’s end. I am going to try a 100-amp lithium battery and 10-gauge wire (20 amp) directly to fridge with a converter to maintain charge. Any recommendations before I spend another fortune for something that doesn’t work? —Kenneth

Dear Kenneth,
The Dometic 4101 is a 10-cubic-foot, two-door refrigerator designed to run on 12-volt power. It has had great reviews from many, including Mike Sokol. It actually draws about 1/2 of the house battery power compared to a residential refrigerator getting 120-volt power from the house batteries through the inverter.

The unit has three modes

Performance Mode: The refrigerator works in AUTO status with five available temperature levels.

Silent Mode: The compressor works at a constant speed while the outer fan works at low speed. The temperature level is limited to level three and below.

ECO Mode: The refrigerator works in AUTO status, but the temperature is limited to level one.

  1. Mode Selection Button
  2. Temperature Section Button
  3. Mode Indicator
  4. Temperature Indicator

If you are experiencing inefficient cooling, the first step is to make sure the air vents in the cooling compartment are not blocked and there is sufficient air flow. Blocked vents would prevent the cold air from flowing into the refrigerator. Also make sure there is sufficient space around the refrigerator cabinet.

Next, check to ensure the door seals are making good contact with the cabinet. An unlevel unit or sprung door that does not seal will allow warm, moist air to enter the refrigerator. Place a dollar bill between the door and the cabinet, shut the door and it should have a slight tug when pulling on the bill. If it slides out easily, the gasket is not sealing. Do this in several locations around the entire door.

Also make sure the refrigerator is not located anywhere close to a heat source such as a converter/charger or water heater that would heat up the compartment.

Next, look at the battery source

If all these are OK, then I would look at your battery source. Does this only happen while dry camping? Or have you tried it plugged into 120-volt power? You stated a reading of 12.4 volts. That indicates it is most likely not plugged in, as your converter would be at least providing 13.2 volts in maintenance or float mode. Plus, a fully charged battery would be 12.6 volts. If it’s lead acid, it might be sulfated and dropping quickly, especially when some other 12-volt component starts drawing.

Your refrigerator has a cut-off voltage of 10.4 volts and won’t cut-in until it reaches 11.7 volts. So you might be getting an on/off condition that will not keep up with the temperature. Plug the unit in to 120-volt power and verify you are getting a steady 13.2 volts and see if that changes the situation. If it works in that scenario, then it is your battery and the lithium would help. But if it doesn’t change, then it’s most likely the temperature sensor on your refrigerator, which is #2 in the diagram.

If you do go with the lithium battery, check the distance of your cable, as Dometic specifications show that the 10-gauge can only have a total distance of 20 feet. And make sure you verify what your converter/charger is putting out so you don’t overcharge or undercharge them. Read the article about swapping out FLA for lithium here.


I sent a rough draft of the above to Kenneth today, and since his original email he did find a fix and sent the following response.

I thank you for all your information.

The fridge is on the other side of the RV from any heat source and the seals are perfect and my 2 house batteries are hooked to a converter.

Unfortunately, my problem was the 3 different mobile services I used as they seem to know very little about the unit and tried everything but listening to an old fighter pilot with the Dometic instructions.

I solved the problems with my solution and advice from a person that understands 12 volts.

We installed in the outside kitchen a 200-amp lithium battery with it’s own converter and charger. The charger is plugged into 110 to properly charge the battery and to provide correct output. The battery is connected to the fridge using-10 gauge wire properly fused. The total length of wires is less than 10 feet, and from battery to fridge is 3 feet. The voltage and amperage is exactly what Dometic specs call for.

The refrigerator works perfectly on the performance, mode maintaining excellent temperatures in both freezer and fridge. The other modes are absolutely worthless as they don’t cool below 50 degrees.

The fridge is installed according to Dometic specifications and the air temperature outside is 65, and inside the trailer with the air conditioning on is 70 degrees on both units.

It’s just not the proper unit for Southern states. If anyone considers it, I strongly suggest going to a local dealership and don’t order on line. This nightmare began with the delivery as it came by 18 wheeler that unloaded on the road in front of my house, as the driver claimed it was general freight. It might look cheaper online, but it’s really a nightmare.

The other option is to seal the outside vents that were for the 110/ propane unit. Perhaps the vents let in too much outside air around the unit. It’s much safer than the old unit, but next time I will buy a new RV instead of fridge.

So it does seem to be a battery supply issue after all. Glad he got it working. I would like to hear from others about using this model refrigerator in hot temps.

 You might also enjoy this from Dave 

Nightmare Dometic refrigerator journey!

Dear Dave,
The refrigerator on propane mode will, all at the same time, shut off flame, click motherboard and check light comes on beeping continuously. When on auto, the refrigerator will beep and motherboard clicks. —Steve, 2022 Jayco 22RB

Read Dave’s answer.

Dave Solberg is a leading expert in the RV industry and the author of the “RV Handbook.”

Read more from Dave here


We have a popular forum for Ask Dave. Please be as brief as possible. Attach a photo or two if it might help Dave with his response. Click to visit Dave’s forum. Or send your inquiries to him using the form below.

Click or drag a file to this area to upload.




3.8 4 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
Don Nedrow
27 days ago

Would it be better to use $10.00 or $50.00 bill to check the door seals? Not a cheap job then. HA HA

Diane McGovern
27 days ago
Reply to  Don Nedrow

😆 Whatever you have handy, Don. Heck, you could even use foreign paper currency and not have to worry about the exchange rate. Have a great day. 😀 –Diane at

26 days ago
Reply to  Diane McGovern

Exchange rate?……now THAT’s funny!!

Diane McGovern
26 days ago
Reply to  Larry

Life’s too complicated as it is. 😆 Have a good night, Larry. 😀 –Diane at

28 days ago

My recommendation? Get rid of the guts of that fridge and replace them with DC residential fridge components. NEVER had an issue since we did the conversion, and the best part? No more fridge fires! One for us was definitely enough!

28 days ago
Reply to  Leonard

It is a DC fridge.

28 days ago
Reply to  Steve

I stand corrected.

Last edited 28 days ago by Leonard
28 days ago

Sounds to me like it is still not working correctly. With those inside and outside ambient temps the fridge should cool better than 50 deg in all modes.

28 days ago

Thanks DAVE! It’s always great to hear a solution to one’s problem. Sometimes we all read stuff and don’t actually hear the outcome. I like the idea of follow-up response on questions. Especially if it is different than what was originally found. I keep your articles in a file for future use as well! Kudos!

David Solberg
28 days ago
Reply to  Ran

I agree! Usually I don’t hear anything after sending the rough draft or the post. Hope readers see this and post results in the comments.

Sign up for the

RVtravel Newsletter

Sign up and receive 3 FREE RV Checklists: Set-Up, Take-Down and Packing List.