A compressor fridge does not pull a steady wattage all day. It cycles on and off, and how long it runs depends on the fridge size, the ambient temperature and how often the lid gets opened. As a rough guide, a 1,440Wh power station will run a 40L fridge for somewhere between a day and a half and three days depending on the weather, and a 60L fridge for a day and a half to two and a half days. The maths below shows exactly where those numbers come from.
| What you need | What to look at |
|---|---|
| A 40L fridge for weekends or blackouts up to a couple of days | BLUETTI AC180P, 1,440Wh with a 500W solar input for fast top-ups |
| A 40L to 60L fridge for week-long off-grid trips | BLUETTI Premium 200 V2, 2,073.6Wh with 1,000W solar input |
| A dedicated fridge and freezer with its own swappable battery, no separate power station needed | MultiCooler Portable Fridge+B70, 716.8Wh packs rated for up to 3 days each |
Power station size calculator
Start from a preset, then tick what you'll run and change the numbers to match your own gear. Watts are on the rating plate or charger.
| Appliance | Qty | Watts | Hours | Wh/day |
|---|
Estimates only. Capacity allows 20% for inverter losses and battery you shouldn't use. Fridge watts are while the compressor runs, and hours are how long it runs in a day, which climbs in hot weather. Check the manufacturer's specs before you buy.
Use the calculator above to plug in your own fridge draw and weather, or read on for the worked examples and the assumptions behind them.
Why fridge draw is never a flat number
A 12V compressor fridge states a running wattage, not a constant one. The compressor kicks in, cools the cabinet down, then shuts off until the temperature creeps back up. How often it kicks in again is the duty cycle, and it is driven almost entirely by ambient temperature, insulation and how often the lid opens.
In mild weather, around 25°C, a well-insulated fridge might run its compressor around 35 percent of the time. On a 40°C day in direct sun, that can climb to 65 percent or more, because the cabinet is fighting a bigger gap between inside and outside temperature. That difference alone can nearly double your daily energy use without the fridge doing anything different.
Worked example: a 40L fridge
Take a 40L compressor fridge drawing 45W while the compressor is running.
| Condition | Duty cycle | Hours running per day | Energy per day |
|---|---|---|---|
| Mild weather (around 25°C) | 35% | 8.4h | 45W × 8.4h = 378Wh |
| Hot weather (around 40°C, in the sun) | 65% | 15.6h | 45W × 15.6h = 702Wh |
This assumes a 40L compressor fridge that runs on its own thermostat, not a figure averaged across 24 hours of continuous draw, and that the fridge is in reasonable shade rather than full sun on the dashboard.
The BLUETTI AC180P holds 1,440Wh rated. Allowing roughly 10 percent for usable capacity and standby drain leaves about 1,296Wh to work with. Run the fridge from the 12V/10A car outlet rather than through the inverter and you avoid inverter losses altogether, since the fridge runs natively on DC.
- Mild weather: 1,296Wh ÷ 378Wh a day = about 3 days
- Hot weather: 1,296Wh ÷ 702Wh a day = about one and a half days
The BLUETTI Premium 200 V2 carries 2,073.6Wh rated. After the same 10 percent allowance that is about 1,866Wh usable.
- Mild weather: 1,866Wh ÷ 378Wh a day = about four and a half days
- Hot weather: 1,866Wh ÷ 702Wh a day = about two and a half days
Worked example: a 60L fridge
A 60L fridge has more volume to cool and typically draws more while running, say 55W.
| Condition | Duty cycle | Hours running per day | Energy per day |
|---|---|---|---|
| Mild weather (around 25°C) | 35% | 8.4h | 55W × 8.4h = 462Wh |
| Hot weather (around 40°C, in the sun) | 65% | 15.6h | 55W × 15.6h = 858Wh |
Same assumptions as above: compressor fridge on its own thermostat, fridge kept out of direct sun where possible.
- AC180P, mild weather: 1,296Wh ÷ 462Wh a day = about two and a half days
- AC180P, hot weather: 1,296Wh ÷ 858Wh a day = about one and a half days
- Premium 200 V2, mild weather: 1,866Wh ÷ 462Wh a day = about 4 days
- Premium 200 V2, hot weather: 1,866Wh ÷ 858Wh a day = about 2 days
The pattern holds across both fridge sizes: moving from mild to genuinely hot conditions roughly halves your runtime, because the compressor is working close to double the hours to hold the same internal temperature. If you are also running lights, a CPAP or charging devices from the same battery, subtract that load's Wh per day before doing this sum. For a wider look at sizing a station for more than just a fridge, see What Size Portable Power Station Do I Need?
What hot weather actually changes
It is tempting to think a 40°C day just means the fridge works "a bit harder", but the duty cycle jump from 35 percent to 65 percent in the tables above is the realistic effect of that heat, not a worst case. Parking the fridge in shade, giving it airflow around the compressor and keeping the lid shut as much as possible all help bring the duty cycle back down closer to the mild weather figure, which is the single biggest lever you have over runtime on a hot trip.
How solar extends runtime
None of the runtimes above account for charging while you camp. If you are stationary with panels out, solar input can claw back a meaningful chunk of what the fridge uses each day, and in good conditions can cover it entirely.
The AC180P accepts up to 500W of solar input and, with prime sunshine, ideal panel orientation and low temperature, charges from 0 to 80 percent in about 2.8 to 3.3 hours. The Premium 200 V2 steps that up to 1,000W max solar input, with BLUETTI quoting a full charge in around 2.4 hours in good sun. Even a few hours of decent sun through the middle of the day can cover a 40L fridge's mild-weather draw of 378Wh, which means the battery stops draining overnight instead of ticking down day after day. For the groundwork on setting up a solar-fed camp, have a look at Mastering Life Off the Grid with Ease.
Or skip the power station altogether
If the fridge is the main reason you need power off-grid, it can make more sense to go with a fridge that carries its own battery rather than sizing a separate power station around it.
The BLUETTI MultiCooler Portable Fridge+B70 Battery Pack is a 3-in-1 fridge, freezer and ice maker with a 40L refrigeration compartment, a 9L ice-making compartment and a 6L battery bay, built around a swappable 716.8Wh B70 battery. BLUETTI rates one B70 pack for up to 3 days of continuous runtime, and two packs for up to 6 days. Because the battery is modular, running flat at camp just means swapping in a charged spare rather than waiting on a charger, and the same B70 pack doubles as power for the AC180T station if you run one. As with any manufacturer-rated runtime, treat "up to" as the mild-weather end of the range: a 40°C day with the ice maker running will draw it down faster, in line with the hot-weather duty cycle jump covered above.
Frequently asked questions
How many watts does a typical camping fridge use?
Most 40L to 60L compressor fridges draw somewhere between 40W and 60W while the compressor is running, not continuously. The number that actually matters for sizing a battery is the duty cycle, how many hours in 24 the compressor is actually on, which is driven mostly by ambient temperature.
Will running a fridge drain my power station faster than other devices?
Not necessarily. Because a fridge cycles on and off rather than drawing continuously, a 45W fridge running 35 percent of the day uses a similar daily total to a much smaller continuous load. The worked examples above show the daily Wh figure you should size against, not the instantaneous wattage on the spec sheet.
Does the weather really make that much difference to runtime?
Yes. In the examples above, moving from a mild 25°C day to a hot 40°C day roughly doubles the compressor's running hours, which roughly halves how many days a given battery lasts. Shade, airflow around the compressor and keeping the lid shut all help bring that back down.
Can solar keep a camp fridge running indefinitely?
If your panel's daily output in good sun meets or exceeds the fridge's daily Wh draw, the battery stops depleting day over day and effectively just tops up what the fridge uses. The AC180P and Premium 200 V2 both list their maximum solar input and charge times above, use those alongside your fridge's daily Wh figure to check whether your setup balances out.
Still not sure which one suits you?
Fridge size, climate and how many days between charges all change the sum, so tell us what you run and where you go and we can help you land on the right number. Get in touch, or browse the full Portable Power range to compare capacities side by side.
