I Tested How Long Will 100ah Battery Run A Fridge?

How long will a 100ah battery run a fridge? Let's test it out!

How long will 100ah battery run a fridge? How long will 100ah battery run a 12v fridge? solar power fridge

The results --- My 12v 100ah lithium (LiFePO4) battery was able to power my 12 volt fridge for 35 hours, despite only being 30% charged.

Based on my results, I can say,

a 12v 100ah lithium (LiFePO4) battery can power a 12v fridge for approximately 100 hours. However, a 12v 100ah lead acid battery will only run a 12v fridge for approximately 40 to 45 hours, due to its 50% depth of discharge limit and 85% discharge efficiency rate.

Video --- How long will a 100ah lithium battery run a fridge?

Here's a video of my test: How long will a 12v 100Ah lithium battery run a 12V fridge?

My test --- how long will a 100ah battery run a fridge?

To find out how long will a fridge run on a 100ah battery i acquired a 12v 100ah LiFePO4 battery and utilized my existing 12v mini RV fridge.

my setup

How long will 100ah battery run a fridge? How long will 100ah battery run a 12v fridge? solar power fridge

I linked my Bateria power's 12v 100ah LiFePO4 deep cycle battery with Whynter's 12v RV fridge using a 12v socket.

my battery arrived with 13.0 volts (meaning 30% charged)

When I received the battery, its voltage was at 13.0 volts, indicating a 30% charge level.

However, I forgot to check the battery manual, which specifies the voltage and corresponding state of charge. Unknowingly, I began the test with only a 30% charged battery.

100ah battery on 12v fridge

The test begins with a 30% charged 12v 100ah lithium battery.

Day 1

I began the test on April 14th at 9:30 in the morning, the fridge was running on a solar battery. finally!

100ah battery on 12v fridge

After about 8 and a half hours, the battery was at 12.7 volts (16% state of charge).

100ah battery on 12v fridge

after 24 hours

Wow! it's been about 24 hours and my 12v fridge is still running on a 100ah LiFePO4 battery.

100ah battery on 12v fridge

After about 24 hours, the battery was at 12.0 volts (9% state of charge). That means my fridge consumed about 21 amps at 12 volts (252 watt-hours) in 24 hours.

100ah battery on 12v fridge
Note: The fridge runs in cycles, which means the compressor turns off when the internal temperature of the fridge reaches its set level. On average, a fridge runs for approximately 20-30 minutes during each cycle, which implies that it consumes power for only half an hour out of every one-hour period.

Day 2

April 15 at 8:30 pm, it's been 35 hours since the fridge is running on a 100ah battery.

100ah battery on 12v fridge

The battery voltage has dropped to 11.1 volts (5% of the charge remains). It's worth noting that this particular battery's voltage is programmed to cut off below 11 volts. Therefore, I'll consider this reading as the final one.

100ah battery on 12v fridge


In the end, a 12v 100ah lithium battery (with 30% charge) lasted 35 hours running a 12v mini RV fridge.

Based on this result, I can say a fully charged 12v 100ah lithium battery will run a 12v fridge for about 100 hours (4 days). And a 100ah lead acid battery will run it for 40 to 45 hours (2 days).

Related post: How Long Will 12v Battery Run A Refrigerator?

Don't expect the same results

How long your fridge can run on a battery depends on a few factors, which are:

  • The outside temperature: If it's hot outside, your fridge will need more power to keep things cold, so it will use up more battery.
  • The size of your fridge: Bigger fridges use more power than smaller ones. Old fridges also use more power than new ones.
  • How much food is in the fridge: If your fridge is full, it will need less power to stay cold than if it's empty.
  • The voltage of your battery: Batteries with higher voltage can last longer than batteries with lower voltage. A 24v 100ah lithium battery will the fridge for about 200 hours or 8 days continuously because it can hold 2400 watt-hours but a 12v 100ah battery can 1200 watt-hours.
  • The type of battery: Lithium batteries can be used up completely, but lead acid batteries can only be used for up to half. Lithium batteries are also more efficient when discharging.
  • The kind of fridge you have: If you've got a 12v DC fridge that means you can directly connect it to a 12v battery. But if your fridge requires AC input (120-220v) then you need an inverter, and inverters are about 90% efficient. So there will be a 10% loss when converting DC into AC power to run your fridge.

Related post: What Size Inverter To Run A Fridge?

7 ways to make your battery last longer on a fridge

Follow these 7 rules to expand the running hours of your 100 amp-hour battery on the fridge.

  1. Fill up your fridge: A fuller fridge needs less energy to stay cool than an empty one. This is because it takes more energy to cool the air inside the fridge than to cool the food.
  2. Leave space around your fridge: Your fridge needs to exchange heat with the surrounding air to stay cool. If it's too close to other objects, it can't get enough air, and it won't work properly. Leave at least 2 inches of space on all sides of your fridge to make sure it can cool efficiently.
  3. Cool your fridge down before you use it: Fridges use a lot of energy to get cold. If you cool your fridge down before you plug it in, it won't use as much energy.
  4. Keep your fridge in a cool place: If the air inside your vehicle is cooler than the outside air, put your fridge inside. This will help it stay cool without using as much energy.
  5. Don't open your fridge too much: Every time you open the fridge, cold air escapes, and the fridge has to work harder to stay cool. Try to open it as little as possible.
  6. Store batteries in the right place: To make sure your batteries work well, keep them in a place with the right temperature. Check the battery label or packaging to see what temperature range is best. It's usually between 20-25°C (68-77°F).
  7. Use eco mode: Some fridges have an eco or low-power mode. This mode uses less energy, but it takes longer to cool things down. If you want to save energy, try using this mode. It will help your battery last longer, and your fridge will still work well.

what size battery to run 12v fridge?

what size battery to run 12v fridge?

Based on my findings, to power a 12V RV fridge for one day, you will need either a 12V 50Ah lead-acid battery or a 12V 30Ah lithium battery.

If you plan on running your fridge for a few days, I would suggest opting for a 12V 50Ah lithium (LiFePO4) battery, or a 100Ah lead-acid or AGM battery.

Here are my recommended battery types in order of preference:

  • 1st choice --- Lithium (LiFePO4)
  • 2nd choice --- AGM
  • 3rd choice --- Lead-acid

Related post: How Many Batteries To Run A Refrigerator?

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I hope this short guide was helpful to you. still, have any confusion? LEAVE A COMMENT or contact us. Thank You!

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I travel around the world in my RV and document my journey on YouTube. I also cover general off-grid and minimalism practices to help you thrive in any tiny living or off-grid situation.

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