Whether you’re living off-grid or you’re in the midst of a power outage, using an inverter to run a refrigerator is a lifesaver.
It enables you to keep your food from spoiling, plus you can relax knowing there’s still fresh milk for your morning coffee.
Once you understand your power requirements, it’s pretty simple to run a fridge off an inverter.
In fact, it can be as simple as it would be to plug into the mains.
All you really need is the correct inverter, battery supply, and your appliance.
If you’re wondering what size inverter for a refrigerator, the best products available, and what else you need to consider then keep reading.
Together, we’ll go through everything you need to know. Plus I’ll throw in all my tips and tricks I’ve learned firsthand over the years.
What Size Inverter for a Refrigerator?
The average home refrigerator uses 60 – 300 watts. So a 1000 watt inverter will run most refrigerators.
The best practice is to use an inverter with a continuous wattage of 20% more than your refrigerator.
So if your appliance draws 500 watts you should use an inverter size of at least 600 watts. This is because inverters are not 100% efficient so this should be accounted for with extra capacity.
You can easily find out the wattage of your refrigerator by checking the manufacturer information in the manual. Plus sometimes it is on a sticker on the appliance. I like to use a wattmeter to get an exact power reading of electronics.
It is also worth saying that refrigerators do not draw a constant amount of power. The wattage peaks and falls throughout the day based on how much cooling needs to be done. Power surges much higher when the compressor is first switched on too. Check your inverter has a peak surge capacity of double the running watts to deal with this. For example, a 1000 watt inverter should have 2000 watt peak power which it can deliver for a few seconds.
Will a 1000 Watt Inverter Run a Refrigerator?
If you’re wondering whether a 1000 watt inverter will power a refrigerator, the answer is yes.
1000 watts should be plenty of power to keep a normal home fridge running. Be sure to check the continuous and peak power of your inverter. You need the continuous power to be 1000W and the peak to be 2000W. The difference is very important as continuous is what can be drawn over a long period of time, whereas peak power only lasts for a number of seconds to deal with surges.
Considerations to Run a Refrigerator on Battery Power
In my experience, there are a couple of very important things to consider when using an inverter to run a refrigerator on battery power.
Pure Sine Wave
You should ensure you use a pure sine wave power inverter. This is the best type of inverter that delivers a smooth consistent flow of electricity. It replicates the AC electricity you get from the mains.
Modified sine wave power inverters are cheaper but will not work efficiently with the inductive load you require. It will cause excess heat and even damage your appliance.
Battery Capacity and Runtime
Next, you need to consider the amount of energy you have stored in your batteries and how long it will last. This can be a little tricky with refrigerators as they don’t use a consistent amount of energy. They are well insulated so don’t always have the cooling system running. You need to find out how much it uses over the course of an hour. You could use a wattmeter to monitor how many amps and watts it uses on average.
Your battery size is measured in Ah (amp-hours) such as 100Ah, 150Ah, 200Ah. This means a 100Ah battery could run for 1 hour if you are drawing 100amp (or 100 hours if you draw 1amp etc).
How Long Will the Inverter Run?
Once you know your refrigerator’s energy consumption and battery capacity you can start to work out how long the inverter will run.
For example, if your appliance uses 50 amps (DC) and you have a 200Ah battery it would last for up to 4 hours.
You can also work out runtime using watts with this formula:
(10 x battery capacity in amp hours) divided by (appliance load in watts)
So let’s say we want to use a 300 watt fridge on a 200Ah battery. Using the formula above we calculate (10 x 200Ah) ÷ 300W = 6.6 hours.
Protip: Lead-acid batteries should only be discharged up to 50% or they will become damaged. For this battery type, the runtime is cut by 50%.
How to Run a Refrigerator on an Inverter (Step-by-Step)
Running a refrigerator on an inverter is very easy to do. Once you have your inverter hooked up, it’s just like plugging into a mains wall socket. Here’s an overview and you can read my guide to Hooking Up an Inverter to a Battery.
Step 1. Connect the red inverter cable to the red battery terminal. (Positive to positive)
Step 2. Connect the black inverter cable to the black battery terminal. (Negative to negative)
Step 3. Switch on the inverter to check it is running correctly – you should see a green LED.
Step 4. Plug your refrigerator into the AC outlet of the inverter. You might hear the inverter cooling fans start running to keep it ventilated. Keep an eye on the inverter screen for input and output readings.
Try not to open your refrigerator door unnecessarily. This lets cold air escape and requires your appliance to work harder and use more energy. You should also switch your inverter off after you disconnect an appliance as it could drain your batteries if left switched on.
Can a Car Power Inverter Run a Refrigerator?
Yes, a car can run a refrigerator with a power inverter. You can connect an inverter to a car battery to run all sorts of appliances. Although, I would avoid running anything too powerful over 500 watts from a small car. Your alternator may struggle to keep your starter battery charged over long periods of time.
Make sure to keep your engine running while using the inverter. If you don’t you will deplete your battery very quickly which will cause damage. Plus you won’t be able to start your engine.
Can I Run a Mini-Fridge Off an Inverter?
You can easily run mini-fridges from an inverter. Most mini-fridges run on far less than 100 watts. This means you can even run them inside a car via the 12V DC cigarette lighter port.
Final Words on Inverters to Run a Refrigerator
I hope this guide gives you a much clearer idea of how to use an inverter to run a refrigerator.
It is actually pretty simple and a 1000 watt inverter should be enough power for your fridge. Plus, make sure it’s pure sine wave for the correct type of output.
With your inverter, you will be able to get AC electricity for your appliances in RVs, boats, trucks, cars, and in the event of a blackout.
Thanks for reading.
