To size a power station, divide its capacity in watt-hours (Wh) by the watts your devices use, then multiply by about 0.85 to allow for conversion losses. A 1,000 Wh unit runs a 100 W load for roughly 8.5 hours. Then check that its output in watts is higher than everything you'll plug in at once.
What's the difference between Wh and W?
Watt-hours (Wh) are capacity: how much energy the battery stores. Watts (W) are output: how much power it can deliver at once. You need enough Wh to last the outage and enough W to start your biggest device.
How long will a power station run my devices?
Use: hours ≈ Wh ÷ device watts × 0.85. The 0.85 is a typical allowance for losses when converting battery power to AC; actual efficiency varies by model, so treat results as estimates.
| Capacity | 50 W load | 100 W load | 500 W load |
|---|---|---|---|
| 500 Wh | ≈ 8.5 h | ≈ 4.3 h | ≈ 0.9 h |
| 1,000 Wh | ≈ 17 h | ≈ 8.5 h | ≈ 1.7 h |
| 2,000 Wh | ≈ 34 h | ≈ 17 h | ≈ 3.4 h |
Find your device's watts on its label or manual. Fridges cycle on and off, so their average draw is lower than their rated power, but they need extra watts for a moment when the compressor starts.
Should I add solar panels?
For outages longer than a day, yes. Solar panels let you recharge during the day, and both EcoFlow and Jackery sell panels and solar-generator bundles, which usually cost less than buying separately.
EcoFlow or Jackery for home backup?
Both offer free US shipping and 30-day returns. Jackery lists a student, key worker and senior discount and a warranty of 2+1 to 5 years depending on model; EcoFlow offers PayPal and Affirm instalments and EcoCredits rewards. See our full EcoFlow vs Jackery comparison.
When is the best time to buy?
The biggest price cuts come around Prime Day and Black Friday. Buy before storm season, not during an outage, when stock and delivery are tight.
FAQs
What size power station do I need for a fridge?
As a rough guide, a fridge averaging 100 W runs about 8.5 hours on 1,000 Wh; check your fridge's label and allow for start-up power.
Can a power station run a whole house?
Portable units power selected devices; whole-home backup needs a much larger system.
Is a power station safe indoors?
Battery power stations produce no exhaust, unlike fuel generators, which must never run indoors.
Related reads: EcoFlow vs Jackery · How to stack discounts · When is Black Friday 2026?
