The two numbers that matter: Wh and W
Every power station has two key specs. Get both right and you'll never be disappointed:
- Capacity (Wh) = how long it lasts. Add up each device's watts × hours per day.
- Output (W) = what it can power at once. It must exceed all devices running together, and its surge rating must handle start-up spikes from motors and compressors.
Quick size guide
| Use case | Typical daily use | Recommended size |
|---|---|---|
| Phones, laptop, lights (weekend camping) | 150–300 Wh | 300–500 Wh |
| CPAP for 2–3 nights | 300–1,000 Wh | 500–1,000 Wh |
| Remote work: laptop, monitor, Starlink | 700–1,200 Wh | 1,000–2,000 Wh |
| Power outage: fridge, Wi-Fi, lights, phones | 1,300–1,800 Wh | 2,000+ Wh or 1,000 Wh + solar |
| Outage with sump pump or well pump | 2,500–4,000 Wh | 3,600 Wh+ (expandable) or a generator |
Wattage of common devices
| Appliance | Running watts | Starting watts |
|---|---|---|
| Refrigerator (full size) | 150 W | 1,200 W |
| Chest freezer | 100 W | 800 W |
| CPAP (no humidifier) | 40 W | 40 W |
| CPAP (with heated humidifier) | 90 W | 90 W |
| Wi-Fi router + modem | 15 W | 15 W |
| Starlink (Standard) | 75 W | 75 W |
| Laptop | 60 W | 60 W |
| Desktop PC + monitor | 300 W | 300 W |
| TV (55" LED) | 100 W | 100 W |
| Microwave (1000 W) | 1,500 W | 1,500 W |
| Coffee maker | 900 W | 900 W |
| Electric kettle | 1,500 W | 1,500 W |
| Space heater (high) | 1,500 W | 1,500 W |
| Window AC (8,000 BTU) | 700 W | 1,800 W |
| Sump pump (1/2 HP) | 1,050 W | 2,150 W |
Look for the label on the back or bottom of your device. If only amps are listed: watts = amps × 120 V.
Buying tips
- Choose LiFePO4 batteries: 3,000+ cycles versus ~500–800 for older NMC chemistry, and safer.
- Expandable units (e.g. EcoFlow DELTA 3, Anker SOLIX C1000X) let you add a battery later instead of buying bigger now.
- Solar input matters for multi-day outages: a higher max solar input means faster recharging.
- Weight: anything above ~2,000 Wh weighs 50 lb or more, so look for wheels.
Frequently asked questions
What size power station do I need for a refrigerator?
A full-size fridge uses about 1.2–1.5 kWh per day and needs ~1,200 W of surge to start. A 1,000–2,000 Wh station with at least 1,800 W output (2,400 W+ surge) is a good fit for a 24-hour outage.
What size power station do I need for camping?
For phones, lights, a fan and a 12 V cooler, 300–700 Wh is enough for a weekend. Add a 100–200 W solar panel for longer trips.
Is 1000Wh enough for a power outage?
It covers essentials for about one day: fridge, Wi-Fi, lights and phone charging. For longer outages, add solar or choose 2,000 Wh+.
Should I add 20% extra capacity?
Yes, a 20% buffer is wise. It covers cold weather, battery aging and devices that draw more than their label says.
Related calculators
Runtime guides by device
- How long will a power station run a refrigerator?
- How long will a power station run a chest freezer?
- How long will a power station run a CPAP machine?
- How long will a power station run a CPAP with heated humidifier?
- How long will a power station run an oxygen concentrator?
- How long will a power station run a Starlink?
- How long will a power station run a Starlink Mini?
- How long will a power station run a TV?
- How long will a power station run a laptop?
- How long will a power station run a window air conditioner?
- How long will a power station run a space heater?
- How long will a power station run an electric blanket?
- How long will a power station run a Wi-Fi router?
- How long will a power station run a mini fridge?
- How long will a power station run a microwave?
- How long will a power station run a coffee maker?
- How long will a power station run a sump pump?
- How long will a power station run a desktop computer?
- How long will a power station run a gaming PC?
- How long will a power station run a game console?
- How long will a power station run an e-bike charger?
- How long will a power station run a box fan?