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How to size a portable power station
Two numbers decide whether a station works for you: capacity in watt-hours and output in watts. Here's how to work out both in five minutes.
Step 1: List what you'll power
Write down every device and its wattage. Use the label, the manual or the appliance wattage chart. For anything that cycles, such as fridges and CPAP heaters, use the average draw.
Step 2: Add up the highest draw at one time
Total the watts of everything that might run at the same moment. The station's continuous output must be higher than this. If a fridge (150 W running) and a microwave (1,100 W) might run together, you need more than 1,250 W.
Step 3: Work out the energy you need
Multiply each device's average watts by the hours you'll run it, then add them up. That's the energy in watt-hours. Divide by 0.85 to cover inverter losses.
Example: a 40 W CPAP for 8 hours (320 Wh) plus a 60 W laptop for 3 hours (180 Wh) = 500 Wh. Divided by 0.85 = about 590 Wh.
Step 4: Pick a size class
| Size class | Typical use | Examples |
|---|---|---|
| About 300 Wh | Phones, laptops, cameras, a router for a few hours | Jackery Explorer 300 v2, Anker SOLIX C300X DC |
| About 500 Wh | A night of CPAP, a mini fridge overnight, weekend trips | EcoFlow River 520 Gen4 |
| About 1 kWh | Two nights of CPAP, half a day of fridge, short outages | Anker SOLIX C1000 Gen 2, Jackery Explorer 1000 v2 |
| About 2 kWh | A full day of fridge, RV weekends, longer outages | Jackery Explorer 2000 v2, Bluetti Elite 200 V2 |
| 4 kWh and up | Whole-home essentials for days, well pumps | EcoFlow Delta Pro 3 |
Step 5: Check the details
Once capacity and output fit, compare weight, solar input, wall recharge time and backup switching speed. If you might need more later, choose a model that takes extra batteries.
The home battery size calculator does steps 2 to 4 for you.