A 12 V compressor fridge/cooler draws about 50 watts while the compressor runs (roughly 35-100 W) and averages about 0.5 kWh a day (around 20 W average) as it cycles in mild weather.
- Running watts
- 50 WTypical; 35–100 W across models
- Starting watts
- NoneNo motor surge
- Per day
- 0.5 kWh24 h of use, cycling
- Current
- 4.2 AAt 12 V while running
Figures checked against DOE, ENERGY STAR and manufacturer data on . Your model's label is the final word.
Watts by model and setting
Most portable fridge models draw between 35 and 100 W while running; a typical one draws about 50 W. Dometic rates its 46 L CFX3 45 at 0.49 kWh per 24 h on DC (fridge at 5 C in 25 C ambient); 50 W x 24 h x 0.42 = 0.5 kWh. Hot weather, freezer mode and frequent opening raise this.
- Ambient temperature: hot cars and sunny campsites make the compressor run much more
- Freezer vs fridge setting: freezing can double energy use
- Size: 35-55 liter models are most common; dual-zone models use more
- Opening frequency, pre-chilling food and keeping it full
- Eco vs max mode settings on the compressor
Running a portable 12V fridge on a generator or power station
- Generator: at least 50 running watts. A generator rated 1,000 W or more covers it with room to spare.
- Power station: continuous output of at least 50 W. Pure sine wave output is the safe choice for motors and electronics.
| Power station capacity | Estimated runtime |
|---|---|
| 500 Wh | 20.2 h |
| 1,000 Wh | 40.5 h |
| 2,000 Wh | 81 h |
| 3,000 Wh | 121.4 h |
Based on 21 W average draw (running watts × duty cycle) and 85% usable capacity.
- Run it from the power station's 12 V DC car-style outlet rather than the AC inverter to avoid conversion losses
- A 500 Wh power station runs a typical 45 L compressor fridge for roughly 2-4 days in mild weather; heat shortens that
- These variable-speed DC compressors start softly, so surge is not a concern for power station sizing
- Use the fridge's low-voltage cutoff setting to protect a vehicle starter battery
Add it to the generator calculator
Questions people ask
How long will a power station run a 12V fridge?
At about 0.5 kWh a day in mild weather, a 500 Wh station lasts around 2-4 days and a 1,000 Wh station about a week, less in hot weather or freezer mode.
How many amps does a 12V fridge draw?
While the compressor runs, typically about 3-5 A at 12 V; Dometic lists a maximum rated current around 8-9 A for its 45-55 L CFX3 models. Averaged over a day it is usually 1.5-2 A.