KeepCold

Is an overnight fridge backup different from 24 hours?

Yes. Eight hours needs about 537.9 Wh on a typical top freezer. A full day needs about 1,613.8 Wh.

Yes. The electrical plan scales with hours. Food-safety clocks do not. USDA’s closed-door refrigerator window is about 4 hours, which is shorter than an 8-hour night. An 8-hour battery plan is not a claim that food stayed safe, and a 24-hour plan is not three USDA windows stacked.

On the certified top-freezer median of 363 kWh a year, 8 hours needs about 537.9 Wh and 24 hours needs about 1,613.8 Wh. The same average load, three times the duration, about three times the watt-hours, because the 10 W idle allowance is in both. A top freezer is often the lower-energy style. A side-by-side or an older unit can need more. Brand is not used.

Pick the duration you actually need the compressor to run. Then read the shortfall. Open the 8-hour estimate or 12 hours

The 24-hour page and the multi-day food page answer the longer questions.

You'll want about 537.9 Wh.

EcoFlow

DELTA 3 Plus + DELTA 3 Series Extra Battery

Published bundle capacity is 2,048 Wh, with 1,800 W continuous and 3,600 W surge.

About 30.5 hours. Energy target met.

Preorder. Ships late November. Startup: unconfirmed.

See preorder details at EcoFlow (opens in a new tab)

EcoFlow

DELTA 3 Max Plus + Smart Extra Battery

Published bundle capacity is 4,096 Wh, with 3,000 W continuous and 6,000 W surge.

About 60.9 hours. Energy target met.

Preorder. Ships in next week. Startup: unconfirmed.

See preorder details at EcoFlow (opens in a new tab)

EcoFlow

DELTA 3 Ultra Plus + DELTA 3 Max Plus Extra Battery

Published bundle capacity is 5,120 Wh, with 3,600 W continuous and 7,200 W surge.

About 76.1 hours. Energy target met.

Preorder. Ships in Mid-December. Startup: unconfirmed.

See preorder details at EcoFlow (opens in a new tab)

Jackery

Explorer 5000 Plus + Battery Pack 5000 Plus

Published kit capacity is 10,080 Wh, with 7,200 W continuous and 14,400 W surge.

About 149.9 hours. Energy target met.

Preorder. ships Nov 28. Startup: unconfirmed.

See preorder details at Jackery (opens in a new tab)

Listed expansion totals are only the combinations on the manufacturer page. Average energy is not both compressors starting together. Runtime does not prove the food stayed safe.

These are estimates. Real runtime depends on your fridge, its age, and how often it's opened.