How to Reduce Energy Use of a 12V Camper van Fridge
The most comfortable camping appliance is a fridge with a 12V system. Cooking menus can be expanded to include anything you could cook at home, as long as it fits in the refrigerator. Portable fridges are becoming increasingly popular additions to any camping and 4WD setup, and if you go out frequently, they soon become well worth the money.
On the other hand, a fridge needs a significant amount of energy to operate since it is usually the most demanding user. You’ll need to get that power somewhere, and there’s a lot of focus on solar panels and batteries. There are several ways you can cut back on your 12V refrigerator’s energy usage.
- How much power does a fridge need?
- What battery should a fridge run off?
- How low can I go with the battery?
- Tips to keep your fridge energy efficient
How much power does a fridge need?
Many different factors affect the energy consumption of a 12V fridge. The power consumption is, in most cases, measured in watt-hours.
A fridge will usually use between 1 and 6 amps depending on the model and whether it’s cold enough inside. The machine’s size, compressor type, ambient temperature, insulation thickness, the target cooling temperature, what you’re using it for and so on are all factors.
While a refrigerator does not operate continuously, it only draws current when the compressor kicks on.
The majority of refrigerators are loud enough to be heard from a few meters away. Others are very quiet, and you have to check the lights on top of them to see if they’re running.
In this example, when the compressor is on, the fridge draws 2.5 amps while running. Let’s say it’s only on for 50% over a 24 hr period; that’s 30 amps per day.
What battery should a fridge run off?
Never leave a refrigerator running on your vehicle’s cranking battery. The battery has a limited amount of stored energy for starting your engine and needs to be kept in good shape. A fridge will draw current from the battery for extended periods, which causes it to wear out.
The most common approach to power a fridge is with a second battery, commonly known as a “deep cycle”.
A vehicle’s cranking battery should be kept in reasonable condition to start the car, while the second battery powers the fridge. This way, you can ensure it’s ready when you need to start your engine. The additional battery does add weight and cost.
You can run them off of a standard cranking battery, but they don’t like to be cycled, and you will severely reduce their lifespan. Lithium batteries are also becoming more popular because of their many benefits, although they have a high price tag.
How low can I go with the battery?
Many people believe that the battery has enough electricity remaining in it because their refrigerator is running. This isn’t accurate – you should not discharge your battery below 50 per cent capacity for lead-acid and 80% for lithium batteries.
A fridge will keep operating well below this level until the low-level alarm goes off and cuts power. The majority of fridges have a low-level cut-off, but not all do.
If you continue to feed power to the fridge, it will still operate down to this threshold but at a reduced speed. Your food won’t be as cold as it should be, and your battery can go flat sooner than expected.
If you have a 100ah deep cycle battery, you should only utilize 50Amps of its capacity before it needs to be recharged. Using the above number of 30 amps is just 1 and 2/3 of a day (without any other usage) before your battery begins to decline.
You’ll need to start your car and allow the alternator to charge the battery after this point or install some solar input. However, things begin to worsen when there are a few overcast days. Using your van or 4wd engine to charge the battery is also a rather pricey strategy.
So, how can you make your 12V refrigerator more energy efficient? In a similar way to keeping ice in an icebox for longer.
Tips to keep your fridge energy efficient
Cool your items before leaving home
Don’t put room temperature items in your fridge if you can help it. It only makes things more difficult and power-hungry. This isn’t a massive issue if you’re still plugged into 240V, but we usually chill foods before putting them in the refrigerator to save energy.
Obviously, if you’re on the go, this is unavoidable; however, as much as possible, pre-chill your food and drinks.
Try To Keep the fridge full
A fully-stocked refrigerator is far more efficient than an empty one. Bottles of water may be used to keep items in your fridge if you run out of food or drink. You’ll save a lot of energy because they don’t change temperature as rapidly as air does when the lid is opened after they’ve been cooled.
Open the lid slowly
When you pull the fridge’s door open and lift up the lid, a significant amount of cold air is drawn out of your refrigerator and sent into the outdoors. The fridge has to cool down the hot air that you’ve pumped into it when you close the lid.
The secret is simple. Gently crack the lid open slowly first, then swing it open normally. This will keep most of the cold air inside, considerably reducing power use.Try
Airflow is imperative
It’s all fine and good to fill your refrigerator to the brim, but if it can’t breathe freely, you’re making it work too hard. Make sure the compressor has adequate breathing space. Consider using a tiny vent or computer fan to help circulation in confined spaces where the fridge is mounted.
On a hot day, it isn’t easy to keep the inside of your camper trailer cool. While this most definitely won’t harm your fridge, it isn’t doing it any favours in terms of longevity and will almost certainly cause it to consume more power.
Keep your fridge as cool as possible
The distinction between a fridge working at a temperature of 25 to 40 degrees is significant. The harder your compressor works in hot air, the higher the operating cost. Obviously, you can only affect so much as far as the ambient temperature is concerned, but you have some say over where your fridge lives.
For example, Parking under a tree will keep your car much cooler and minimize the amount of work the refrigerator has to do. If you are parked in the sun, open the back of your car so it does not overheat.
A lot of refrigerator manufacturers provide covers for their fridges. These help to preserve the fridge while also improving its insulation. The less heat entering your fridge and the less cold air that can escape, the better insulated your fridge is.
Touch the outside of your fridge when it is running next time. If the fridge’s temperature is significantly cooler than the air around you, the insulation allows the cold air to dissipate.
Time and number of times opened
The longer you leave your fridge open, and the more times you open it in a day, the less power efficient it will become. Make a practice of grabbing what you need and shutting the lid as soon as possible.
If you know that you’re cooking something up, consider what you’ll need before going to the fridge. I’m not suggesting that you should only open the refrigerator a few times a day; it’s ridiculous. Anything you can do to limit how frequently you enter the fridge is beneficial.
Consider purchasing an icebox for storing beverages close to save you from having to open the refrigerator too often.
Shut the lid properly
It’s simple to throw the lid back and forget about the latches, but any air that finds its way into the fridge is the air that must be cooled. This is why some people will spend more on latches for their fridges than on their entire refrigerator itself.
Don’t ignore your fridge’s lid, even if it doesn’t have a latch to hold it shut. Shutting the door entirely without bumping it helps to keep cold air inside.
Check the wiring
The power being supplied to your fridge needs to be the right-sized wiring. If it’s too tiny, the fridge will work less efficiently.
Overheating is generally caused by a bad connection between the battery and the fridge powerpoint, mainly if it runs from the front to the back. Running 6mm wire is recommended at least.
Use a quality fridge
Finally, if you’ve bought a low-cost fridge and it’s chewing the electricity, it’s time to upgrade. Engel, Dometic, Evakool, Bushman, and myCOOLMAN are just a few of the companies that have built up a solid reputation!
Check out our review on the Bushman caravan fridges.
There’s nothing more refreshing than being able to grab a cold drink from your fridge in the middle of nowhere. Take advantage of the luxury and try to limit energy usage, but consider upgrading your solar/battery system if it still uses too much.
What sort of 12V fridge do you use? Let us know in the comments.
Wade & Dani
Hi! We’re Wade and Dani, We’re currently travelling around Australia in our 2017 Mercedes Sprinter Camper van and sharing our best experiences, stories, reviews and adventures as we go along. Make sure you follow long on our Instagram