What size power station keeps a refrigerator running?
Short answer, then the math.
An average full-size refrigerator needs about 1,500 watt-hours per day from a power station — so a 2,000Wh-class station covers a full 24 hours with margin. A 1,000Wh-class station covers roughly 8–12 hours: enough for an overnight outage or to bridge until the grid returns, but not a full day.
Everything below shows how those numbers are derived, so you can substitute your own fridge’s numbers and reproduce the answer.
Why the fridge sticker lies
Your refrigerator’s door sticker shows a power rating — say, 150W. That number is misleading in three ways.
Rated watts ≠ running watts. The sticker figure is a maximum or nominal rating. The compressor draws less while it runs.
The compressor doesn’t run all the time. It cycles on and off. The fraction of time it’s running — the duty cycle — is typically around one-third (25–40%) for a household fridge in normal conditions.
Startup surge. When the compressor kicks on, it briefly draws a spike of current — typically 5–8× its running watts for a fraction of a second. (Estimate — your manual may state it exactly.) A 150W-running fridge can briefly pull 750–1,200W. Your station’s surge rating must clear that spike.
The best real number you have: your fridge’s EnergyGuide label lists estimated annual kWh. Divide by 365 for average daily use.
The 3 numbers that matter
| # | Number | What it decides | Example (this article) |
|---|---|---|---|
| 1 | Running watts | Whether the inverter can handle the load at all | 150W |
| 2 | Startup surge | Whether the station’s surge/peak rating clears the compressor’s kick-on spike | ~750–1,200W (Estimate) |
| 3 | Daily watt-hours | What battery capacity you need | ~1,260Wh/day (Estimate) |
The worked example
Assume: 150W running, 35% duty cycle, 24 hours.
Step 1 — daily energy the fridge consumes: 150W × 0.35 × 24h = 1,260Wh (Estimate)
Step 2 — what the station must hold. We assume 85% inverter efficiency: 1,260Wh ÷ 0.85 ≈ 1,482Wh of station capacity (Estimate)
Step 3 — keep a reserve. We plan with a 20% reserve: 1,482Wh × 1.2 ≈ 1,780Wh rated capacity for a full 24-hour day (Estimate)
Round it: a 2,000Wh-class station covers a full day with margin.
Why 1,000Wh usually isn’t enough for a full day
A 1,000Wh station delivers roughly 850Wh after inverter loss (Estimate). Against our ~1,482Wh daily need, that’s about 57% of a day — 13–14 hours drained to empty, or ~11 hours keeping the 20% reserve (Estimates).
Which capacity tier fits which scenario
Surge ratings below are Manufacturer specifications, checked 2026-10-15 (per each product record). Estimated runtimes assume our example fridge (150W, 35% duty cycle, 85% efficiency, 20% reserve).
| Scenario | Need (Estimate) | Tier | Examples — price checked 2026-10-15 |
|---|---|---|---|
| ~8 hours (overnight / short outage) | ~590Wh | 1,000Wh class | BLUETTI AC180 — 1,152Wh, $499.00 · EcoFlow DELTA 3 — 1,024Wh, $629.00 · Anker SOLIX C1000 Gen 2 — 1,024Wh, $549.99 |
| ~24 hours (a full day) | ~1,780Wh | 2,000Wh class | BLUETTI AC200L — 2,048Wh, $899 · BLUETTI Elite 200 V2 — 2,073.6Wh, $899 · EcoFlow DELTA 3 Max — 2,048Wh, $899 |
| ~48 hours (multi-day outage) | ~3,560Wh | 3,600Wh class | EcoFlow DELTA Pro — 3,600Wh, $1,799 |
A closer look at each tier’s examples:
1,000Wh class — the overnight tier.
- BLUETTI AC180 — 1,152Wh, 1,800W continuous output, 2,700W surge. 35.3 lbs, 5-year warranty (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
- EcoFlow DELTA 3 — 1,024Wh, 1,800W continuous, 3,600W surge. Recharges in about 56 minutes on AC, expandable to 5kWh, 5-year warranty (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
- Anker SOLIX C1000 Gen 2 — 1,024Wh, 2,000W continuous, 3,000W peak. 24.9 lbs — the lightest of the three — with ~49-minute AC recharging (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
2,000Wh class — the full-day tier.
- BLUETTI AC200L — 2,048Wh, 2,400W continuous. 62.4 lbs (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
- BLUETTI Elite 200 V2 — 2,073.6Wh, 2,600W continuous, 3,900W surge. 53.4 lbs (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
- EcoFlow DELTA 3 Max — 2,048Wh, 2,400W continuous, 4,800W surge, 0–80% recharge in about 68 minutes (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
3,600Wh class — the multi-day tier.
- EcoFlow DELTA Pro — 3,600Wh, 3,600W continuous, 7,200W surge. About 99 lbs; expandable with extra batteries for longer outages (Manufacturer specification). Check price [Affiliate link — we may earn a commission.]
Every one of these clears our example fridge’s ~750–1,200W startup spike on continuous output alone. Surge is rarely the binding constraint on a fridge — capacity is.
What changes the math
Duty cycle. The 35% in our example is a middle estimate. A fridge in a hot garage opened constantly can run a 50–60% duty cycle; a fridge in a cool basement barely opened can drop to 25%.
Second loads. A 2,000Wh station covering your fridge for 24 hours has roughly 200Wh of headroom left. Add a 65W laptop charging for three hours and you’ve spent most of it.
When in doubt, use your EnergyGuide number (annual kWh ÷ 365) instead of our 150W/35% example.
Substitute your own fridge
- Read your EnergyGuide label: annual kWh ÷ 365 = daily Wh.
- Divide by 0.85 for inverter loss.
- Multiply by 1.2 for a 20% reserve.
- Pick a station with at least that rated capacity, then confirm its continuous output clears your fridge’s running watts.
Example: a 480 kWh/year fridge → 1,315Wh/day ÷ 0.85 × 1.2 ≈ 1,857Wh → a 2,000Wh-class station (Estimates).
Your next step
Run your exact fridge through the Outage Brief calculator — the fridge preset pre-loads typical running watts and duty cycle. It applies the same inverter-efficiency and reserve math above to every station in our database.
And if you want one short email a week with deal prices and sizing walkthroughs like this one, join the Outage Brief newsletter.
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