The size of a power station is its capacity in watt-hours (Wh). To pick one, you work out how much energy your devices use during an outage. This guide shows the math, a worked example and which published models fit each size band. Prices are as of November 8, 2026. Many are sale prices, and some models are pre-orders.
The formula
Energy use is power times time. The U.S. Department of Energy gives the same method for estimating appliance energy use: multiply watts by hours of use. A watt-hour is one watt for one hour. So:
Wh needed = watts x hours
A 60 W device running for 10 hours needs 600 Wh. Find the watts on the device label or in its manual. Your own numbers matter more than any average.
Plan for losses
A power station stores direct current and runs your devices through an inverter, which converts it to household AC. That conversion wastes some energy as heat. The usable energy is less than the listed capacity. Our planning margin in the example below is 15 percent. That figure is our assumption, not a maker's number, so add more if you want a safer cushion.
A worked example: fridge and lights
These wattages are example values, not data from our tables. Check the label on your own appliances.
| Load | Assumed use | Energy |
|---|---|---|
| Refrigerator | 150 W while running, about 8 hours of running in 24 | 1,200 Wh |
| 5 LED bulbs | 10 W each, 5 hours | 250 Wh |
| Total for one day | 1,450 Wh |
Divide by 0.85 to cover a 15 percent loss: 1,450 / 0.85 is about 1,706 Wh. For a one day outage, you want a unit with at least 1,706 Wh. For two days, double the daily total first: 2,900 / 0.85 is about 3,412 Wh.
Now check power, not just energy. A fridge compressor draws more for a moment when it starts. Your unit's output in watts must cover everything running together, and its surge rating should cover the start-up spike. All the models below list at least 1,500 W of output.
Which models fit each band
Capacity and prices come from the makers' US pages.
| Need | Model | Capacity | Output | Price |
|---|---|---|---|---|
| Up to about 1,000 Wh | Anker SOLIX C1000 Gen 2 | 1,024 Wh | 2,000 W | $549.99 |
| Up to about 1,000 Wh | BLUETTI AC180 | 1,152 Wh | 1,800 W | $499 |
| Up to about 1,000 Wh | Jackery HomePower 1000 v2 | 1,024 Wh | 1,500 W | $559 |
| 1,500 to 2,100 Wh | Anker SOLIX F1500 | 1,536 Wh | 1,800 W | $599.99 |
| 1,500 to 2,100 Wh | Anker SOLIX S2000 | 2,010 Wh | 1,500 W | $729.99 |
| 1,500 to 2,100 Wh | BLUETTI Elite 200 V2 | 2,073.6 Wh | 2,600 W | $899 |
| 1,500 to 2,100 Wh | Anker SOLIX C2000 Gen 2 | 2,048 Wh | 2,400 W | $999.99 |
| 3,000 to 3,850 Wh | BLUETTI Elite 300 | 3,014.4 Wh | 2,400 W | $1,199 |
| 3,000 to 3,850 Wh | EcoFlow DELTA 3 Ultra | 3,072 Wh | 3,600 W | $1,299 |
| 3,000 to 3,850 Wh | Jackery HomePower 3000 | 3,072 Wh | 3,600 W | $1,499 |
| 3,000 to 3,850 Wh | BLUETTI Elite 400 | 3,840 Wh | 2,600 W | $1,499 |
| 5,000 Wh and up | Oukitel BP5000 Pro Max | 5,120 Wh | 5,000 W | $1,899 |
| 5,000 Wh and up | Anker SOLIX S5000 | 5,024 Wh | 4,500 W | $2,499.99 |
Our example one day need of about 1,706 Wh fits the 2,000 Wh class. The two day need of about 3,412 Wh fits the 3,840 Wh BLUETTI Elite 400 or any 5,000 Wh unit. Watch output as well as capacity. The S2000 lists 1,500 W, enough for a fridge and lights but not a large load. The Elite 400 has the most capacity below 5,000 Wh but lists 2,600 W.
Grow later
If you are unsure, start small and add batteries. The EcoFlow DELTA 3 goes from 1,024 Wh to 5,000 Wh. The Jackery HomePower 1000 Plus v2 goes to 11,000 Wh. The Anker SOLIX F3000 goes from 3,072 Wh to 12,288 Wh.
Add solar if outages run long
Panels refill the battery during the day, so a smaller unit can last longer. Check each model's solar input limit before you buy.
Rankings
Compare the options on these lists: home backup, under $1,000, under $2,000, expandable and solar. For more on picking a unit, read how to choose a home backup power station.
