in short, a 12v 50Ah Lithium deep cycle battery will last about 20-24 hours running a 12v (4.5 Cu. Ft.) fridge and about 9 hours while running a medium size kitchen fridge (14 Cu. Ft.). After this, your battery will be fully depleted, So if you have a lead-acid type battery then the runtime will be half
Need a simple solution? use the calculator given below to figure out how long will a 12v deep cycle battery or a car battery run your RV refrigerator, camping fridge, or kitchen fridge.
Battery Runtime Calculator
Note! if you're looking for the right size battery bank for your fridge then read my in-depth post on how many batteries to run a fridge
Instructions
- Most of the fridges require AC power so you'd need an inverter but if you have a small 12v fridge you can run directly from the battery with the help of a DC-DC converter
- The total load will be the power consumption of your fridge in one hour including duty cycles (which I'll explain in a bit)
- After entering the values click on CALCULATE BUTTON to figure out the battery backup time
Assumptions
- Inverter efficiency: 85%
- Lead-acid battery: 50% depth of discharge limit
- Lithium (LiFePO4) battery: 100% depth of discharge limit
In-depth breakdown? There are a few variables that will determine the battery runtime on your refrigerator. and also I'll share some key points to get the maximum from your batteries when running the fridge
Factors That Will Affect The Battery Runtime
These are the main factors that will determine the battery runtime on a fridge or refrigerator
- Battery Capacity
- Wattage consumption of fridge per hour
- inverter efficiency
Now let's dive deep into calculation stuff so you can estimate the closest battery runtime.
1- How many watts does a refrigerator use per hour?
On average new technology, refrigerators consume about 60-350 watts of power when running (depending on the size) but on the other hand, an old technology fridge (manufactured before 2010) will consume about 400- 700 watts of power. The daily total power consumption will range between 0.5-2.8kWh and 3.2-5.6kWh
The specific power consumption value will depend mainly on the capacity, energy efficiency, and environmental factors
Duty Cycle - The fridge will turn itself on and off according to the cooling requirement inside the refrigerator this on and off cycle is called the duty cycle,
So on average a fridge runs about 20-30 minutes per hour and 8-12 hours in 24 hours (depending on the fridge technology and the amount of food inside the fridge)
To find out the power consumption of your fridge, check the product specs sheet which is usually located on the back side of the fridge.
❝ or use a watt meter, plug this in between the power socket and the fridge socket it will show you the total power consumption of your fridge in the total running hours. This is the most accurate way to calculate the power consumption of any appliance. i would highly recommend buying one, this will help you in a long run ❞
If you have a new model fridge it should be mentioned as estimated yearly power consumption, if it doesn't have any then there will be amps and volts mentioned as shown in the pic
Watts = Amps * Votls
Use this formula to calculate the wattage consumption of your fridge.
115 * 1.1 = 126 watts Note! This will be the amount of power consumption when your fridge is running.
Now divide it by 3 to find out the average power consumption per hour. (duty cycle)
126 / 3 = 42 watts A small fridge consumes about 40-50 watts of power per hour
Video – Tips To Decrease The Power Consumption of Your Fridge
2 - Battery Capacity
Here's a chart of different size 12v batteries in watt-hours (wh)
| 12v Battery Capacity | Useable Watt-hours (Lead-acid 50% DoD limit) | Useable Watt-hours (Lithium 100% DoD limit) |
|---|---|---|
| 50Ah | 300 Wh | 600 Wh |
| 70Ah | 420 Wh | 840 Wh |
| 100Ah | 600 Wh | 1200 Wh |
| 150Ah | 900 Wh | 1800 Wh |
| 200Ah | 1200 Wh | 2400 Wh |
| 300Ah | 1800 Wh | 3600 Wh |
Related: Amps To Watts Calculator: How Many Watts In A 12-volt Battery?
Now minimize the power loss which will occur due to inverter inefficiency. Which will be between 15%-10%
For Example
12v 100Ah lead-acid battery watt-hours after DC-AC conversion loss
600 * 0.85 = 510 AC wattsMust Read: Solar DC Watts To AC Watts Calculator & Formula
How Long Will a 12v Battery Run a Refrigerator? - chart
Here's a chart on how long will a 12v battery run any size refrigerator
| 12v battery (50% DoD limit) | Fridge Size | Est. Runtime (hrs) |
|---|---|---|
| 50Ah | Camping fridge (2.5-5 cu. ft) | 12-9 hrs |
| 50Ah | Kitchen fridge (10-15 cu. ft) | 6-4 hrs |
| 50Ah | Kitchen fridge (15-22 cu. ft) | 3-1.5 hrs |
| 100Ah | Camping fridge (2.5-5 cu. ft) | 24-18 hrs |
| 100Ah | Kitchen fridge (10-15 cu. ft) | 12-8 hrs |
| 100Ah | Kitchen fridge (15-22 cu. ft) | 6-3 hrs |
| 150Ah | Camping fridge (2.5-5 cu. ft) | 36-27 hrs |
| 150Ah | Kitchen fridge (10-15 cu. ft) | 18-12 hrs |
| 150Ah | Kitchen fridge (15-22 cu. ft) | 9-4.5 hrs |
| 200Ah | Camping fridge (2.5-5 cu. ft) | 48-36 hrs |
| 200Ah | Kitchen fridge (10-15 cu. ft) | 24-16 hrs |
| 200Ah | Kitchen fridge (15-22 cu. ft) | 12-6 hrs |
Summary
- On average, a 12v battery will last between 10-30 hours while running a fridge/refrigerator. The exact value will highly depend on the capacity of the battery, its depth of discharge limit, and the size of a refrigerator.
Related Post: Solar Panel Calculator For Battery
Chart - How long will a 100ah battery run a fridge?
12v 100Ah Lead-acid Battery Runtime on a Fridge
| Fridge Type | Average Wattage Consumption (Per hour) | Est. Runtime with 100ah lead-acid battery |
|---|---|---|
| 12v mini fridge (2 cu. ft.) | 20 watts | 24 hrs |
| camping fridge (4.5 cu. ft.) | 30 watts | 17 hrs |
| kitchen fridge (10 cu. ft.) | 40 watts | 12 hrs |
| kitchen fridge (15 cu. ft.) | 50 watts | 10 hrs |
| kitchen fridge (20 cu. ft.) | 80 watts | 7 hrs |
| kitchen fridge (22 cu. ft.) | 100 watts | 5 hrs |
| kitchen fridge (25 cu. ft.) | 120 watts | 4 hrs |
| kitchen fridge (28 cu. ft.) | 170 watts | 3 hrs |
Summary
- 12v 100Ah lead-acid battery with 50% DoD limit will run a 12v mini camping fridge for about 24 hrs
- 12v 100Ah lead-acid battery with 50% DoD limit will run an apartment size fridge for about 12 hrs
- 12v 100Ah lead-acid battery with 50% DoD limit will run a large size kitchen fridge for about 7 hrs
12v 100Ah Lithium (LiFePO4) battery runtime on a fridge
| Fridge Type | Average Wattage Consumption (Per hour) | Est. Runtime with 100ah Lithium battery |
|---|---|---|
| 12v mini fridge (2 cu. ft.) | 20 watts | 48 hrs |
| camping fridge (4.5 cu. ft.) | 30 watts | 34 hrs |
| kitchen fridge (10 cu. ft.) | 40 watts | 24 hrs |
| kitchen fridge (15 cu. ft.) | 50 watts | 20 hrs |
| kitchen fridge (20 cu. ft.) | 80 watts | 14 hrs |
| kitchen fridge (22 cu. ft.) | 100 watts | 10 hrs |
| kitchen fridge (25 cu. ft.) | 120 watts | 8 hrs |
| kitchen fridge (28 cu. ft.) | 170 watts | 6 hrs |
Summary
- 12v 100Ah Lithium battery with 100% DoD limit will run a 12v mini camping fridge for about 48 hrs
- 12v 100Ah Lithium battery with 100% DoD limit will run an apartment size fridge for about 24 hrs
- 12v 100Ah Lithium battery with 100% DoD limit will run a large size kitchen fridge for about 14 hrs
Chart - How long will a 200ah battery run a refrigerator?
12v 200Ah lead-acid battery runtime on a fridge
| Fridge Type | Average Wattage Consumption (Per hour) | Est. Runtime with 200ah lead-acid battery |
|---|---|---|
| 12v mini fridge (2 cu. ft.) | 20 watts | 48 hrs |
| camping fridge (4.5 cu. ft.) | 30 watts | 34 hrs |
| kitchen fridge (10 cu. ft.) | 40 watts | 24 hrs |
| kitchen fridge (15 cu. ft.) | 50 watts | 20 hrs |
| kitchen fridge (20 cu. ft.) | 80 watts | 14 hrs |
| kitchen fridge (22 cu. ft.) | 100 watts | 10 hrs |
| kitchen fridge (25 cu. ft.) | 120 watts | 8 hrs |
| kitchen fridge (28 cu. ft.) | 170 watts | 6 hrs |
Summary
- 12v 200Ah Lead-acid battery with 50% DoD limit will run a 12v mini camping fridge for about 48 hrs
- 12v 200Ah Lead-acid battery with 50% DoD limit will run an apartment size fridge for about 24 hrs
- 12v 200Ah Lead-acid battery with 50% DoD limit will run a large size kitchen fridge for about 14 hrs
12v 200Ah Lithium (LiFePO4) battery runtime on a fridge
| Fridge Type | Average Wattage Consumption (Per hour) | Est. Runtime with 200ah lead-acid battery |
|---|---|---|
| 12v mini fridge (2 cu. ft.) | 20 watts | 96 hrs |
| camping fridge (4.5 cu. ft.) | 30 watts | 68 hrs |
| kitchen fridge (10 cu. ft.) | 40 watts | 48 hrs |
| kitchen fridge (15 cu. ft.) | 50 watts | 40 hrs |
| kitchen fridge (20 cu. ft.) | 80 watts | 28 hrs |
| kitchen fridge (22 cu. ft.) | 100 watts | 20 hrs |
| kitchen fridge (25 cu. ft.) | 120 watts | 16 hrs |
| kitchen fridge (28 cu. ft.) | 170 watts | 12 hrs |
Summary
- 12v 200Ah Lithium battery with 100% DoD limit will run a 12v mini camping fridge for about 96 hrs
- 12v 200Ah Lithium battery with 100% DoD limit will run an apartment size fridge for about 48 hrs
- 12v 200Ah Lithium battery with 100% DoD limit will run a large size kitchen fridge for about 28 hrs
How Long Will a 12v 120ah Battery Run a Fridge
| Fridge Type & Capacity | Est. Runtime with 12v 120ah Lead-acid battery (50% DoD limit) | Est. Runtime with 12v 120ah Lithium battery (100% DoD limit) |
|---|---|---|
| 12v mini fridge (2 cu. ft.) | 28 | 56 |
| camping fridge (4.5 cu. ft.) | 20 | 40 |
| kitchen fridge (10 cu. ft.) | 14 | 28 |
| kitchen fridge (15 cu. ft.) | 12 | 24 |
| kitchen fridge (20 cu. ft.) | 10 | 20 |
| kitchen fridge (25 cu. ft.) | 7 | 14 |
| kitchen fridge (30 cu. ft.) | 5 | 10 |
Summary
- 12v 120Ah Lead-acid battery with 50% DoD limit will run a 12v mini camping fridge for about 28 hrs and a 12v 120Ah lithium battery with 100% DoD will run a 12v mini camping fridge for about 56 hours
- 12v 120Ah Lead-acid battery with 50% DoD limit will run an RV fridge for about 12 hrs and a 12v 120Ah lithium battery with 100% DoD will run a 12v mini camping fridge for about 24 hours
- 12v 120Ah Lead-acid battery with 50% DoD limit will run a large kitchen-size fridge for about 10 hrs and a 12v 120Ah lithium battery with 100% DoD will run a 12v mini camping fridge for about 20 hours
How long can you run a fridge on a car battery?
A car battery is typically 48-70Ah which is equal to 576-840Wh (wh = ah*volts). But the car batteries have a depth of discharge limit of 50% so which means you can only use 290-420Wh of power.
So to find out the runtime of your car battery on the fridge divide the battery capacity in Wh by fridge power consumption per hour.
For example, a 70ah car battery will run a small camping fridge for about 20 hours.
How Long Will Dometic Fridge Run On Battery?
Dometic is famous for its portable RV/camping refrigerators, i have seen most people are also searching for how long will their Dometic fridge last on a battery.
in short, On average Dometic fridge consumes about 30-40 watts of power per hour (with 20 minutes of the compressor running time in an hour). So a 12v 100Ah Lithium battery will last about 27-36 hours, which in result will fully discharge the battery so if you have a lead-acid type battery it will last half of the time
Steps to find out the battery runtime of your Dometic fridge.
- Find out the fridge's average power consumption per hour
- Enter the values in the calculator to find out the battery runtime
Note! Dometic fridge support AC & DC current, so if you're thinking about running your fridge on a DC current (directly from the battery) make sure the voltage of your battery and your fridge input DC voltage should be the same. And most importantly use an DC-DC voltage regulator when running your fridge directly from the battery. But i would always recommend using a pure sine wave inverter to run a fridge.
Other Useful Posts
- Calculate What Size Solar Panel For Fridge (Using Our Calculator)
- What Size Inverter To Run A Fridge?
- Solar Battery Charge Time Calculator + (Tips To Reduce Charge Time)
- How Long To Charge 12v Battery With Solar panel? – Calculator
I hope this short guide was helpful to you. still, have any confusion? LEAVE A COMMENT or contact us. Thank You!
