Waeco/Dometic Coolmatic CD30 drawer fridge

Published 29th August 2017
Updated 31st May 2023

I’m installing a kitchen under the bed. A CD30 drawer fridge is perfect for this. It’s only 25cm high but holds 30 liters. Downside off course is the fact that you can’t store taller items standing up.

Energy efficiency

It’s a compressor fridge and energy efficient. The manual claims it uses 40 watts but some testing shows it only uses 2.2 amps @ 13,9V (about 30 watts) when the compressor and cooling fan are running with a small spike to 3 amps when the compressor kicks in. The requested temperature and the ambient temperature will determine how often the compressor and fan will run. The 110 watts solar panel and 110Ah AGM battery should provide enough power to run the fridge for 24 hours.

Changing the cut-off voltage

Back side of the Waeco CD30 fridge

Back side of the Waeco CD30 fridge

The fridge is equipped with a battery monitor which switches the compressor off to protect the battery when a low voltage is detected. It should switch off at 10.4 volts. and switch back on at 11.7 volts. Unfortunately, it’s insanely sensitive. I had it shut off at 12+ volts and start a turn off/turn on cycle.

Granted, the manual states you should use 4mm2 up to 8mm2 cables depending on length and I used 2.5mm2 which is plenty for the 3 amp load. Other people solved similar problems by beefing up the diameter. If you still have to install, use at least 4 mm2. I changed the cut-off voltage because I couldn’t run a new cable.

The Waeco manual doesn’t mention anything about changing or disabling the cut-off voltage. The fridge is equipped with a Secop 101N0650 controller board. The manual for this Secop controller board carries some interesting information. First of all, at 12 volts, 2.5mm2 cable should be enough for a 2.5meter run (page 6). Second, it documents how you can change the cut-off voltage using resistors or even a small piece of wire (page 10). The controller board is on the back of the fridge. By connecting a resistor with a specified value between terminals C and P, the resulting cut-off value will increase or decrease. I didn’t have any luck using resistors, but using 0 ohm (plain wire) worked perfectly. The cut-off value is now set to 9.6 volts and I haven’t had any issues with it for the last few months.

Word of caution: if you change the cut-off voltage, you are responsible for not running your battery down and possibly damaging it. Also, this change might void your warranty.

Ventilation and insulation

The unit doesn’t make much noise and most of it is coming from the fan. Considering the fridge will be under the bed, I expect it will be muffled to enough to not be a nuisance during the night. The ventilation is following a kind of “maze”. This will probably help with keeping the noise down. The fan will take air at floor level behind the water tanks. The warm air will be expelled underneath the sink.


  1. Dave Smithe on 8th August 2018 at 1:58 am

    Is it difficult to move the compressor to the side of the unit?

    • Tom on 8th August 2018 at 8:05 am

      Hi Dave, the compressor and electronics are mounted on a tray which you can unbolt from the back. The copper pipes between the compressor and the drawer are flexible but would require you to bend them carefully.That would be a but scary. Both the pipe and the wiring are long enough to relocate the tray. Mounting the tray to a wall would be the most convenient way to secure the compressor. The Waeco is designed to offer this flexibility. You can check the manual using the link in the article. Please let me know if you successfully moved the compressor. I will keep it in the stock location.

  2. Marcus on 20th November 2018 at 11:24 am

    Thanks for the pics and info

  3. Nale on 15th August 2019 at 10:35 pm

    I moved the compressor. Just turned it and put it on top the fridge. It is scary and you gotta bend the pipe carefully bit by bit with holding it on two sides of where you want the bend to be, so the force isn’t delivered to a part of the pipe that’s further away (have seen pictures where it came off), but I have never done something like that before and managed.

  4. Tom on 16th August 2019 at 2:13 pm

    You’re a brave soul, Nale. 😀 I didn’t dare to do it.

  5. Greg on 12th May 2020 at 11:15 pm

    Hi. I moved it to the side without an issue. Just follow the natural flow of the pipe, and screw it into position on the side. You may need to expand the pipe a little to match the screw holes, but no major bending required.

    • Leigh on 5th June 2021 at 12:43 pm

      Hey Greg. Can you please give me a measurement from the front of the fridge to the back after moving the compressor?

  6. Mike on 22nd May 2021 at 12:34 am

    I’m looking at that same unit for my L400 Delica – trying to decide (A) if it’s enough space, and (b) if the drawer version (rather than opening on top) would make the space less efficient. Do you have any insights now that you’ve been using it for a while? I’m currently thinking between the Dometic or an Alpicool C30.

  7. Tom on 23rd May 2021 at 9:11 pm

    I have only been using it on a few day trips so far. In two weeks, we’ll go on a 2 month trip. With a 100 watt solar panel and the fridge being so energy efficient, I expect my 110 ah AGM to not run out as long as I have half decent weather. One downside is the fact that you cannot have anything standing up. Bottles and milk cartons need to lie down. Something you need to take into account while grocery shopping.

  8. Darla on 26th July 2021 at 5:36 am

    I have had this fridge for a few years and love it. But I run it via the mps-50 US power supply to 110v. Whenever I’ve connected it directly to a 12v battery or even connected a battery to the battery terminals on the mps-50 it will not run. What am I missing?

    • Tom on 26th July 2021 at 11:24 am

      Hi Darla, assuming your battery is in good working order: you probably have problems with the low voltage cutoff. It seems that it’s a bit too sensitive on this fridge. Most people have solved this by using short 4 mm2 power cables. I solved it by adjusting the low cutoff voltage. I’ll do a writeup on it soon.

      • Kai Grundmann on 31st August 2021 at 9:00 pm

        Das Einstellen der Abschaltspannung würde mich sehr interessieren.

        • Tom on 3rd September 2021 at 3:54 pm

          Hi Darla and Kai, I just added instructions for changing the cut-off voltage.

        • michelle on 4th November 2021 at 6:51 am

          I’m a total newbie to camp fridges and I’m definitely not understanding the watts or voltage lingo means. I’m just the average woman who expected to plug the cd30 into a cigarette plug.. it came with 2 bare wires .. can I wire up a cig plug and use that? I’ve recently been to an auto electrician and he thinks that would work… but they turned out shonky so need advice badly .

          • Tom on 7th November 2021 at 10:14 pm

            Hi Michelle, the fridge probably won’t be happy if you wire it up like that. It needs fairly short and thick wires. Cigarette plugs aren’t wired up that way. You’ll run into the issues I mentioned under “cut-off voltage”.

  9. Ben on 27th May 2023 at 12:43 pm

    I’ve had one of these fridges for the past 7 years. Mine would cut out at about 12.2v which is perfect. By running your battery down lower that that you almost certainly do permanent damage. 11.7v is completely flat. Hopefully people reading this understand the key point about voltage drop because adjusting it to cut in at 11.7v when you’ve got little/no voltage drop is a very bad idea.
    For the same of anyone thinking of buying one be aware that there is a fundamental flaw in the design of the drawer. The drawer sides are only half the height of the fridge compartment so if you more than half fill the fridge the food on the top falls over the sides and ends up at the back behind the drawer and prevents the drawer from closing. The drawer can’t be removed so you need someone with very thin long arms to reach over the back to get the food out. It’s really maddening. I’ve attached a sheet of plastic to the back of the drawer to raise the height to prevent this happening.

  10. Tom on 31st May 2023 at 2:02 pm

    Hi Ben, thanks for your additional comments. That;’s why the article contains the warning. You can however remove the drawer. On both sides, the rail contain a small black plastic lever, one pointing up and one pointing down. If you switch both of them, you can pull out the drawer. I added a picture of it.

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