Could your Caravan Fridge Problems be due to your Car?

Hi, I’m Chris, I run Horton Common along with my father Robert.

Being the owner of a small caravan site I get quite a lot of feedback from guests about their caravans. What they like, what they don’t and also whats stopped working. Over recent years I have had a number of guests talk to me about caravan fridge problems. Some would state that their fridge would work fine on gas. However, they were having problems with their fridge working via mains electricity and 12V.

There are various reasons why you can get problems with a caravan fridge not working properly. For instance, it’s very important to properly level your caravan to make sure the fridge works efficiently.

Caravan Fridge Problems
There are various issues which can lead to caravan fridge problems.

Occasionally, I’ve also had guests describe problems with the fridge not working properly while towing. However, I was recently made aware by one guest that caravan fridge problems may be down to the purchase of a new car! I was rather perplexed by this, so I started to look into it a bit more. I then came across the video below which explains why new cars with Euro 6 engines may be to blame for some caravan fridge problems.

Learn why Euro 6 engines used in new cars may be to blame for some caravan fridge problems.

Caravan Fridge Problems and Euro 6 Engines

Engines used in cars are not that clean emissions wise as we know (Diesel Gate cough cough). However, there new sets of standards which come around roughly every 5 years. The current highest standard for car engines is Euro 6, which was introduced in 2015. You can read more about what Euro 6 engines are and how they work in this AutoExpress article. Essentially the key objective is the reduce the nitrous oxide (NOx) and particulate (black dust) emissions which both petrol and diesel engines produce.

Regenerative Braking on Euro 6 Engines

So the key issue with caravan fridge problems and Euro 6 engines is around the feature of regenerative breaking. Typically the alternator on a normal car is putting power back into the battery by placing that load on the engine. Well, to improve fuel efficiency, Euro 6 engines take that alternator load away from the engine and captures it from the car’s brakes, under braking conditions.

For regenerative breaking to work there has to be somewhere for that energy to go. Therefore the computer (ECU) on a Euro 6 engine keeps the car’s battery at a lower state of charge/voltage ready to absorb that energy. Hence here lies the problem. As the battery on the Euro 6 engine is now only held at 12.4V, where older cars would be at 14V.

DC Power and Long Cables

Direct current (DC) as used in vehicles loses voltage the longer cables get. Now, a car is fairly short, just a couple of meters long. Therefore voltage loss within the car is not a problem. However, to go from a cars battery to a caravan fridge, there can be 8m of cable, potentially even more. Therefore voltage loss suddenly can become an issue.

Caravan Fridge 12V
This graph shows the voltage drop from the car’s battery to the caravan fridge which can cause problems. – Image: SterlingPowerLtd

As I’m sure you know, your caravan fridge when running from the leisure battery requires 12V to work. As stated above a Euro 6 car will have a battery potentially as low as 12.4V. Therefore after that power has travelled through 8m+ of cables, it could actually be below 12V. Hence the caravan fridge can develop problems and stop working.

However, as stated in the video above, the voltage coming from the car while towing may actually be as high as 15V. Well, in that case, the problem might be that the caravan fridge trips out because the voltage is too high!

Potential Damage to the Caravan Fridge?

So there is potentially a situation, say going up and down hills where the car’s battery is fluctuating between 12-15V over a relatively short period of time. Causing the caravan fridge to turn on and then trip out quite frequently. Besides obviously not being great for your food stored in the fridge, it also makes you think is that damaging the fridge? I personally have no idea, but I can’t imagine its good for it. It makes me wonder if some of the guests I’ve spoken to with mains electrical issues and their fridges could be linked to this problem.

Associated issues with Leisure Batteries and Caravan Movers

So the issues of a low voltage being sent to a caravan from Euro 6 car potentially creates other problems. First, your leisure battery will not have been maintained at a reasonable state of charge.

The leisure battery is probably depleted from trying to run the caravan fridge because the car is not providing enough power to do so. Therefore, many people probably think this is an issue with their leisure battery being old or faulty and not an issue with their new car. Moreover, this can lead to an issue with your caravan motormover.

Caravan Motor Mover
You need well over 12V from your leisure battery to use your motor mover – Image: Powrtouch Classic

You arrive on site, and you want to set up your caravan. After turning the remote control on for your motormover …. nothing happens. I know from personal experience, if you are not well over 12V on the battery meter you don’t have a chance at getting your motor mover to work. Therefore this voltage issue with Euro 6 engine cars is potentially causing more problems than just your fridge not working.

Solutions to the Problem

Essentially your not going to fix this problem within your car, you need to focus on your caravan. If only 9-12V is reaching the caravan, then before that goes into the fridge or leisure battery it needs to be boosted in voltage. The video above is produced by Sterling Power Ltd. They offer a battery-to-battery charger. At this time of checking the price is just under £230.

Sterling Power Battery to Battery Charger
The Sterling Power Battery to Battery Charger could potentially address certain caravan fridge problems.

There are potentially other products on the market that can perform the same task of providing a more consistent and suitable voltage to the caravans electrical system. So make sure to look around, compare prices and warranties etc.

How do you check if a car has a Regenerative Braking Alternator?

Originally on this post, I stated the easiest way to check if your car has regen braking was to get a friend to watch a DC voltage meter plugged into the car’s cigarette lighter. However, Simon who owns caravanchronicles.com kindly informed me that simply won’t work.

Apparently, cars have a ‘buck converter’ to protect the vehicle’s electronics from voltage peaks. So you won’t see the spike in DC voltage which can happen with regen braking. Simon stated you need either a voltage meter or multimeter connected directly to the car’s battery to see the spikes in voltage.

Quick Note on Leisure Battery Charging

You should not be depending on your car or mains hook up when it comes to properly charging and maintaining your battery. A good portable leisure battery charger is something every caravan and motorhome owner needs to own.

Conclusions on Caravan Fridge Problems due to New Cars

Now, this issue with caravan fridges and new Euro 6 cars does not appear to be prevalent in all cases. There are various forum posts from individuals stating they have never experienced such an issue with their new cars.

The fact is there are lots of variables at play. Certain makes of caravan fridge may be more sensitive to voltage changes than others. Some caravan manufactures may be aware of this issue and have fitted additional electrical equipment to regulate the voltage. However, if it sounds like an issue which may be the reason for problems you’re experiencing with your caravan fridge, it may be worth looking into.

I hope you found this post useful and informative and I hope you consider visiting us at Horton Common and our fully serviced pitches in the future. 🙂

Chris - Site Manager

Hi, I’m Chris, I along with my father Robert we operate and maintain Horton Common.

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