The Outage PlannerBackup power math for homes and RVs

Power station runtime calculator: how long will it run your devices?

By , The Outage Planner · Updated · Power station sizing

Last checked: November 1, 2026. Capacities and output ratings come from each manufacturer's own spec page, linked below. We recheck them every three months and whenever a new model is added.

Short answer: runtime in hours = battery capacity (Wh) x 0.85 / your device's watts. The 0.85 allows for the energy lost turning battery power into household AC power, and it's the factor Jackery uses in its own runtime formula. So a 1,000 Wh power station runs a 100 W load for about 8.5 hours, a typical top-freezer fridge for about 20 hours, and a 50 W device for about 17 hours.

Pick a model or type your own numbers into the calculator, or read your answer straight off the runtime chart.

Runtime calculator

The calculator needs JavaScript. If it doesn't load, use the chart below or the formula: Wh x 0.85 / watts.

Finding your device's watts. Look at the label or the manual for watts (W). If it only lists amps, multiply amps by volts: 1.5 A at 120 V is 180 W. A label shows the maximum, so a fridge or a CPAP usually averages less. For a fridge, the yellow EnergyGuide label's kWh per year divided by 8,760 hours gives a fair average: 365 kWh a year is about 42 W. A plug-in watt meter gives the real number.

Inverter standby. When the AC outlets are switched on, the inverter uses power just to stay on. Jackery publishes it as standby consumption: 18 W on the Explorer 1000 v2 and 12 W on the Explorer 300 Plus. With small loads this matters a lot. If your device can run from the 12 V car port or USB-C, untick the box.

Runtime chart by battery size

Hours of runtime at a steady load, using the 0.85 factor and ignoring standby draw.

Rated capacity 25 W 50 W 100 W 200 W 500 W 1,000 W
300 Wh 10 h 5.1 h 2.5 h 1.3 h 0.5 h 0.3 h
500 Wh 17 h 8.5 h 4.2 h 2.1 h 0.8 h 0.4 h
1,000 Wh 34 h 17 h 8.5 h 4.2 h 1.7 h 0.8 h
2,000 Wh 68 h 34 h 17 h 8.5 h 3.4 h 1.7 h
3,000 Wh 102 h 51 h 26 h 13 h 5.1 h 2.5 h

A 300 Wh class unit can't run a 500 W or 1,000 W load at all if its output is rated lower. The Explorer 300 Plus is rated 300 W. Always check the continuous output rating as well as the capacity.

Model Capacity Rated AC output Standby on AC Source
Jackery Explorer 300 Plus 288 Wh 300 W 12 W Jackery basic information
Jackery Explorer 1000 v2 1,070 Wh 1,500 W (3,000 W surge peak) 18 W Jackery basic information
EcoFlow DELTA 3 Plus 1,024 Wh 1,800 W (3,600 W surge) Not published on the spec page EcoFlow
Anker SOLIX C1000X 1,056 Wh 1,800 W (2,400 W surge) Not published on the spec page Anker SOLIX
Jackery Explorer 2000 v2 2,042 Wh See Jackery's spec page Not published on the spec page Jackery

These are examples to make the math concrete, not recommendations. Any model works in the calculator: choose "Other" and type its capacity.

Real devices, worked out

These use published figures. Treat the hours as estimates: your own device and conditions will differ.

Device Average draw 1,024 Wh unit such as the DELTA 3 Plus (870 Wh usable at 0.85) Where the draw comes from
ENERGY STAR top-freezer fridge About 41 W (0.99 kWh a day) About 21 hours Median of ENERGY STAR certified models, from our fridge sizing guide
ENERGY STAR bottom-freezer fridge About 63 W (1.52 kWh a day) About 14 hours Same
ENERGY STAR side-by-side fridge About 73 W (1.75 kWh a day) About 12 hours Same
ResMed AirSense 11 CPAP 56.1 W typical About 15.5 hours, or about 12 hours on AC with 18 W standby ResMed AirSense 11 user guide, from our CPAP runtime guide

Example scenario (an illustration with stated assumptions, not a real household): a family wants to keep a top-freezer fridge (41 W average) and a Wi-Fi router (assume 12 W from its label) running through a 24-hour outage on the AC outlets of a 1,070 Wh unit with 18 W standby. Total draw is 71 W. Usable energy is 1,070 x 0.85 = about 910 Wh. Runtime is 910 / 71 = about 12.8 hours, so they'd need to recharge once, from solar or a car, or add a second battery.

Outside the US

The same watt-hour math works in the UK, Canada and Australia. The difference is the outlets: UK and Australian homes run on 230 V, so buy the version sold in your country. Jackery's UK/EU and Australian Explorer 1000 v2 have 230 V, 50 Hz outlets with the same 1,070 Wh battery and 1,500 W rating as the US model (Jackery Europe, Jackery Australia manual). Canada uses 120 V like the US. A plug adapter doesn't change the voltage.

Make your power last longer

Sources

Checked November 1, 2026.

Have a measured reading for a device we don't list? Send it to us.

Quick answers

How do I calculate how long a power station will last?

Multiply the battery capacity in watt-hours by 0.85 to allow for conversion losses, then divide by the watts your device uses. A 1,000 Wh power station running a 100 W load lasts about 1,000 x 0.85 / 100 = 8.5 hours. The 0.85 factor is the one Jackery uses in its own runtime formula.

How long will a 1,000 Wh power station run a refrigerator?

About 12 to 21 hours for a typical full-size fridge, depending on its type. A typical ENERGY STAR top-freezer fridge averages about 41 W over a day, which gives about 21 hours; a side-by-side averages about 73 W, which gives about 12 hours.

Why does my power station run out sooner than the calculator says?

The usual reasons are the inverter's own standby draw when the AC outlets are on (18 W on the Jackery Explorer 1000 v2), a device that draws more than its average, cold or hot batteries, and battery aging. Using DC outlets where your device allows it avoids the inverter loss.

Does this work for UK, Canadian and Australian power stations?

Yes. The watt-hour math is the same everywhere. Just buy the model sold for your country: UK and Australian versions have 230 V outlets, while US and Canadian models have 120 V outlets.