How Long Will A 100ah Battery Run A Fridge? + Calculator

Curious about ” how long will a 100Ah battery run a fridge? ”

in this short guide, I’ll explain it with the help of charts and the factors which will affect the 100Ah battery runtime on the refrigerator.

How Long Will A 100ah Battery Run A Fridge? In short, a 12v 100Ah lead-acid battery with 50% depth of discharge will run a small size camping fridge (2-5 cu. ft.) for about 18-24 hours and a large-sized kitchen fridge (20-25 cu. ft.) for about 6-8 hours.

Hate calculations? use the calculator given below to find out the 100Ah battery runtime on a fridge

Battery Runtime Calculator

Battery Capacity
Ah
Battery Volts
V
Select Battery Type
Load Connected with inverter?
Total Load (watts)
Wh

Calculator Assumptions

  • Lead-acid battery: 50% DoD (depth of discharge) limit
  • Lithium (LiFePO4): 100% DoD (depth of discharge) limit
  • Inverter efficiency: 90% efficient

How to use the calculator

  • Battery Capacity: Enter battery capacity in Amp-hours (Ah) in this case it’ll be 100
  • Battery Volts: Enter battery voltage, is it 12, 24, or 48v?
  • Load Connected with inverter? is your fridge running through the inverter or is it running directly from the battery (which is possible if you have a 12v fridge and a 12v battery but in this case also you would have to install a DC-DC voltage regulator to protect the refrigerator from voltage fluctuations)
  • Total Load: Will be the average total power consumption of the fridge (Per hour) including duty cycles, keep reading to figure out the power consumption of your fridge

After putting the values click CALCULATE “ to find out the estimated runtime of your 100Ah battery on the refrigerator.

Example

Suppose you have a 12v mini camping fridge (4.5 cu. ft.), which consumes about 700Wh of power in 24 hours, and a 12v 100Ah lithium (LiFePO4) battery. Which can be discharged 100%

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

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

12v 100Ah Lithium (LiFePO4) will run a 12v mini camping fridge for about 40 hours. After this, your battery will be fully depleted, so if you have a lead-acid or AGM battery then it will run for about 20 hours

Note: in order to recharge your batteries you’d need the right size solar panel. use my free online solar panel calculator for battery

Related Post: Solar Panel Calculator For Battery

How Much Power Does a Refrigerator Use?

On average latest technology, refrigerators consume about 60-350 watts of power when running and 0.5-2.5kWh per day. but on the other hand, an old technology fridge (manufactured before 2010) consumes about 400- 700 watts of power and 3.2-5.6kW per day. The specific power consumption value will depend mainly on the capacity, energy efficiency, and environmental factors

To calculate the accurate power consumption of your fridge read the product description sheet on your fridge to find out.

What size inverter do i need to run a fridge?

if you have a new model fridge there will be an estimated “yearly power consumption” by the company but if it doesn’t then calculate the wattage consumption of your fridge with this formula (watts = amps*volts)

let’s take my medium size RV fridge as an example (mentioned above)

115 * 1.1 = 126.5

This fridge will consume 126 watts of power when the compressor is running.

Duty Cycle: new technology fridge runs about 8-10 hours per day in total (depending on external or internal factors).

On the other hand, if you have an old technology fridge I’ll have a duty cycle of about 12-15 hours.

126 * 8 = 1000Wh or 1kWh

Medium size RV fridge consumes about 1kWh of power per day with 8 hours of duty cycle.

Note! To get started, the fridge requires a surge wattage (burst of power which will last for a few seconds) which is usually about 2-3 times higher than the continuous wattage consumption of the fridge.

Why am i telling you this? because you’d need the right size inverter to handle this surge wattage. which i have explained in detailed

Must Read: What Size Inverter To Run A Fridge?

Need an easy and accurate solution? use this watt meter to find out the total power consumption of any appliance, place this meter between the outlet and the fridge cable plug and leave it for 24 hours. after 24 hours it’ll show you the total power consumption during this period of time.

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Watch this short and quick video to save electricity usage of your fridge/refrigerator.

How Long Will a 100Ah Battery Run A Fridge? – Chart

Here are some charts on how long will a 12v, 24v, or 48v 100Ah battery will last on a different size fridge.

How Long will a 12v 100Ah Battery Run a Fridge?

Fridge Type & CapacityEst. Runtime with 12v 100ah Lead-acid battery (50% DoD limit)Est. Runtime with 12v 100ah Lithium battery (100% DoD limit)
12v mini fridge (2 cu. ft.)2448
camping fridge (4.5 cu. ft.)1734
kitchen fridge (10 cu. ft.)1224
kitchen fridge (15 cu. ft.)1020
kitchen fridge (20 cu. ft.)816
kitchen fridge (25 cu. ft.)612
kitchen fridge (30 cu. ft.)48
Table: how long will a 12v lead-acid and lithium (LiFePO4) battery will run a fridge

Summary

  • 12v 100ah lead-acid battery will run a medium size RV fridge (10 cu. ft.) for about 12 hours and 12v 100Ah Lithium (LiFePO4) battery will run for 24 hours
  • 12v 100ah lead-acid battery will run a large size kitchen fridge (20-22 cu. ft.) for about 8 hours and 12v 100Ah Lithium (LiFePO4) battery will run for 16 hours

How Long will a 24v 100Ah Battery Run a Fridge?

Fridge Type & CapacityEst. Runtime with 24v 100ah Lead-acid battery (50% DoD limit)Est. Runtime with 24v 100ah Lithium battery (100% DoD limit)
camping fridge (4.5 cu. ft.)3468
kitchen fridge (10 cu. ft.)2448
kitchen fridge (15 cu. ft.)2040
kitchen fridge (20 cu. ft.)1632
kitchen fridge (25 cu. ft.)1224
kitchen fridge (30 cu. ft.)816
Table: how long will a 24v lead-acid and lithium (LiFePO4) battery will run a fridge

Summary

  • 24v 100ah lead-acid battery will run a medium size RV fridge (10 cu. ft.) for about 24 hours and 24v 100Ah Lithium (LiFePO4) battery will run for 48 hours
  • 24v 100ah lead-acid battery will run a large size kitchen fridge (20-22 cu. ft.) for about 16 hours and 24v 100Ah Lithium (LiFePO4) battery will run for 32 hours

Related: What Size Solar Panel To Charge 24v Battery?

How Long will a 48v 100Ah Battery Run a Fridge?

Fridge Type & CapacityEst. Runtime with 48v 100ah Lead-acid battery (50% DoD limit)Est. Runtime with 48v 100ah Lithium battery (100% DoD limit)
camping fridge (4.5 cu. ft.)3468
kitchen fridge (10 cu. ft.)2448
kitchen fridge (15 cu. ft.)2040
kitchen fridge (20 cu. ft.)1632
kitchen fridge (25 cu. ft.)1224
kitchen fridge (30 cu. ft.)816
Table: how long will a 48v lead-acid and lithium (LiFePO4) battery will run a fridge

Summary

  • 48v 100ah lead-acid battery will run a medium size RV fridge (10 cu. ft.) for about 48 hours and 48v 100Ah Lithium (LiFePO4) battery will run for 96 hours
  • 48v 100ah lead-acid battery will run a large size kitchen fridge (20-22 cu. ft.) for about 32 hours and 48v 100Ah Lithium (LiFePO4) battery will run for 64 hours

How To Calculate How Long Will a Battery Run a Refrigerator

Calculate Battery Size For Inverter

Step 1: Calculate the battery capacity in watt-hours

To calculate the battery capacity in watt-hours use this formula

Battery Watt-hours = Battery capacity Ah * Battery voltage

For example

12v 100Ah battery in watt-hours?

100 * 12 = 1200Wh or 1.2kWh 

Now if you have a lead-acid, AGM, or Gel battery multiply the value by 0.5 to calculate the useable wattage

1200 * 0.5 = 600Wh

12v 100Ah battery will give you 1.2kWh of useable power if you have a lithium battery and 600Wh of power if you have a lead-acid battery

Related Post: Amps To Watts Calculator: How Many Watts In A 12-volt Battery?

Step 2: Subtract the DC to AC conversion loss

Multiply the inverter efficiency rate with battery watt-hour capacity

For example

you have a 90% efficient inverter (which you can check on the specs sheet of your inverter)

600 * 0.90 = 540Wh

Related Post: Solar DC Watts To AC Watts Calculator

Step 3: Calculate The Fridge Wattage Consumption Per Hour

I have discussed this in the above session if you haven’t read it.

I’ll take a medium size RV fridge as an example which consumes about 40 watts per hour

Step 4: Divide the fridge power consumption by battery capacity (Wh)

Battery Runtime = battery useable watt-hour capacity/Fridge wattage consumption (per hour)

For Example

let’s take medium size RV fridge which on average consumes about 40 watts of power per hour and a 12v 100Ah battery with a 100% depth of discharge limit with 90% inverter efficiency

540 / 40 = 27 hours

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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!

I'm an experienced Sales Consultant with a demonstrated history of working in the renewables and environment industry. Skilled in Photography, Customer Service, and Sales.

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