Dometic CFX40 Fridge running on Leisure Battery Problem

Johnny_h

Johnny_h

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Hi,
Has anyone else experienced this issue before? My Dometic CFX40 Fridge runs fine off mains voltage however once running off 12v from the leisure battery it fails to keep a constant temperature i.e. it sounds as though the fridge is trying to kick in the compressor but fails repeatedly.

I've tested the battery with a multimeter and it's reading 12.98v, same reading from the 12v socket.

I have a 2014 Cali Beach and the battery looks to be the original Varta 5K0 915 105 H 12V 80Ah battery.

Any similar experiences?

Thanks
John
 
Last edited:
Hi,
Has anyone else experienced this issue before? My Dometic CFX40 Fridge runs fine off mains voltage however once running off 12v from the leisure battery it fails to keep a constant temperature i.e. it sounds as though the fridge is trying to kick in the compressor but fails repeatedly.

I've tested the battery with a multimeter and it's reading 12.98v, same reading from the 12v socket.

I have a 2014 Cali Beach and the battery looks to be the original Varta 5K0 915 105 H 12V 80Ah battery.

Any similar experiences?

Thanks
John
Others have reported something similar basically related to Voltage drop on the 12v line including the plug.
What they have done is replace that line with thicker wire grade and using low resistance Anderson Connectors to connect directly to the Leisure Battery.

Read from Post 8 onwards.

 
We had multiple problems with our CFX28 cutting out overnight due to voltage drop. (It was always fine in daylight because we have solar panels trickle charging the leisure battery at 14.4 volts.) The issue is solved now by hard wiring the fridge to the battery using good quality cable.
 
I had two issues, one the connections on the leisure battery were very loose once investigated and two the socket in the beach had voltage drop.

I fixed a separate shortish fused wire for the fridge direct to battery and problems all went away.
 
The fridge has three low voltage cutout settings:
Hi - 11.8
Med - 11.2
Lo - 10.1

If the voltage at the fridge socket falls below the set level it will cut out to preserve the battery.

Setting the voltage cutout to Lo might resolve your problem.

Note that a voltage of 10.2 at the fridge does not imply 10.2 at the battery which could well be +2 volts as the cigarette lighter contacts are particularly poor.
 
Yes that is also the underload voltage so it is likely to be higher at rest. I can usually get away with medium.
 
To rekindle this issue a year on.. I have an ‘18 Cali Beach and a CFX28. this last trip, the temp was set at 3° but gradually started rising to 6, 7 then 8° on days 3 and four of operation. It was pretty sunny and the solar charger reached ‘Float’ most days with voltage in the high 12s and the fridge running.

Turning it off and on again had no effect.
I caved and started the engine for 15mins on day four and rapidly got the temp down to 3°.

Do you guys think I can resolve this issue by bypassing the B-Pillar 12v socket? Unsure why the voltage at the socket would cause this on day 4 but not day 2 given that solar was topping up. Don’t suppose you have a link for what you used or how you cured it? Thanks. Stu


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Even when my leisure battery was new and charged (and reading high 12s) , my CF26 would struggle to start on the B pillar socket. Wiring direct to the battery and now it reliably starts until the voltage drops to low 12s.
 
To rekindle this issue a year on.. I have an ‘18 Cali Beach and a CFX28. this last trip, the temp was set at 3° but gradually started rising to 6, 7 then 8° on days 3 and four of operation. It was pretty sunny and the solar charger reached ‘Float’ most days with voltage in the high 12s and the fridge running.

Turning it off and on again had no effect.
I caved and started the engine for 15mins on day four and rapidly got the temp down to 3°.

Do you guys think I can resolve this issue by bypassing the B-Pillar 12v socket? Unsure why the voltage at the socket would cause this on day 4 but not day 2 given that solar was topping up. Don’t suppose you have a link for what you used or how you cured it? Thanks. Stu


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Hi S2 there are lots of discussion on this issue and how some have overcome it

Here’s one that Amarillo @Amarillo started which created a whole raft of other post
 
To rekindle this issue a year on.. I have an ‘18 Cali Beach and a CFX28. this last trip, the temp was set at 3° but gradually started rising to 6, 7 then 8° on days 3 and four of operation. It was pretty sunny and the solar charger reached ‘Float’ most days with voltage in the high 12s and the fridge running.

Turning it off and on again had no effect.
I caved and started the engine for 15mins on day four and rapidly got the temp down to 3°.

Do you guys think I can resolve this issue by bypassing the B-Pillar 12v socket? Unsure why the voltage at the socket would cause this on day 4 but not day 2 given that solar was topping up. Don’t suppose you have a link for what you used or how you cured it? Thanks. Stu


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When camping we set our fridge temperature to 6C. Nothing stays in there for more than four days, and at 6C for four days nothing is going to go off.

Those cigar lighter sockets are an outdated design for 12V supply, and were never designed for the purpose of continuous electric supply - only to provide a hot element to safely light a fag while driving.

I really think that your best bet is to hardwire the fridge to the leisure battery for a reliable 12 volt supply.

Put a big fuse (50amp) close to the battery to protect the battery, and an appropriate small fuse close to the fridge to protect the fridge's internal fuse.

I started with this for £9.07 from AT Leads and Looms:
1597705698044.png

And then in its simplest form all you need do is snip off the cigar plug from the fridge lead and attach an Anderson connector.

Our setup is somewhat more complex with all sorts of extension leads and two way splitters meaning we can power our fridge, 12v lighting or other 12v appliances from behind the passenger seat, from the jack compartment in the boot, or externally.
 
Hi S2 there are lots of discussion on this issue and how some have overcome it

Here’s one that Amarillo @Amarillo started which created a whole raft of other post

Thanks for this. That’s a very helpful thread and not sure how I missed it other than finding this one first and getting excited that I actually searched for something and found it
thanks @Amarillo and everyone who contributed, for the original rundown.

Love this place - just imagine if it served beer


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