Fridge and freezer backup

Estimate how long a power station can cover a fridge or freezer.

Use running watts, duty cycle, surge, battery watt-hours, and outage length to compare practical power station sizes.

Estimated runtime16.2 hours

A 1000Wh class station may cover a short fridge outage.

Inputs

Appliance and battery

Measured energy per day (optional)Best input: run the appliance through a watt meter for 24 hours and enter kWh.EnergyGuide annual kWh (optional)Use the yellow EnergyGuide label when a 24-hour measurement is not available.Running wattsUse measured watts or the appliance label as a starting point.Duty cycle35% means the compressor runs about 21 minutes per hour.Startup surge wattsCheck the power station surge rating before buying.Power station capacityUse the listed watt-hours, such as 500Wh, 1000Wh, or 2000Wh.Usable battery percentAccounts for inverter losses, reserve, and real-world headroom.Outage targetUsed to estimate the battery size needed for your goal.

Input priority: measured daily kWh, then EnergyGuide annual kWh, then running watts and duty cycle.

Why this is only an estimate

Refrigerators and freezers cycle on and off. Room temperature, door openings, food load, age, and compressor behavior can change runtime. Use a plug-in watt meter when the purchase depends on the number.

Fridge and freezer guides

Plan around runtime, surge, and recharge

Guide

Power station size for a refrigerator

Understand the checks that matter before relying on a battery during an outage.

Read guide

Freezer

Garage freezer outage backup

See why freezer runtime depends on load, temperature, and compressor cycling.

Read guide

Battery math

Amp hours to watt hours calculator

Convert Ah to Wh before comparing 12V batteries for fridge or freezer backup.

Open calculator