What will actually keep your fridge running when the power goes out?

Solar Backup Lab publishes verified manufacturer specifications and runtime calculated from them, with the arithmetic shown. No star ratings, no invented test results, no claims of hands-on testing we did not do.

Start with the number that matters

Capacity in watt-hours is the headline figure, but it is not what you get. The inverter loses roughly 15% converting stored DC into household AC, so a 1,070 Wh unit delivers about 910 Wh in practice. Then it depends entirely on what you plug in — and on duty cycle, because a refrigerator's compressor only runs about a third of the time.

Every runtime on this site comes out of those two lines. Work through our full runtime reference to see 20 common household loads calculated against each unit.

The three units we cover

All three are LiFePO4, all three are in the 1,000–1,200 Wh class, and all three will run the essentials through a typical outage. They differ in weight, recharge behaviour and how far they expand.

Answering the actual question

• Will one of these run my refrigerator, and for how long? — the most common question, worked through properly including compressor surge.
• Backing up a CPAP — the strongest case for battery backup, and the humidifier trap that ruins the maths.
• How to size a unit for your household — build your own load list rather than guessing.
• Solar vs a gas generator — an honest comparison, including where gas still wins outright.
• The runtime reference — 20 loads × 3 units, calculated.

Why there are no star ratings here

Because we have not tested these units, and a score derived from a spec sheet is decoration pretending to be evidence. Sites that award a 4.8 to hardware they have never plugged in are guessing with extra steps. We would rather hand you the specifications, the formula and the contradictions we found in the manufacturers' own documentation, and let you decide. That is the whole method, written out on our methodology page.