Choosing the right size portable power station is the most important decision you will make. Too small and it will not run what you need. Too large and you waste money and lug around unnecessary weight. Here is a practical guide to help you calculate exactly what you need.
The Simple Formula
Total Watt-Hours Needed = (Wattage of Device × Hours of Use Per Day) × Number of Days
Power Consumption Reference Table
| Device | Typical Wattage | Daily Usage | Daily Consumption |
|---|---|---|---|
| Smartphone charger | 15W | 3 hours | 45Wh |
| Laptop | 60W | 6 hours | 360Wh |
| LED light (10W bulb) | 10W | 6 hours | 60Wh |
| Mini fridge (3.2 cu ft) | 60W avg | 24 hours | ~500Wh |
| Full-size refrigerator | 150W avg | 24 hours | ~1,200Wh |
| CPAP machine (no humidifier) | 30W | 8 hours | 240Wh |
| CPAP with heated humidifier | 60W | 8 hours | 480Wh |
| 40-inch LED TV | 80W | 4 hours | 320Wh |
| Microwave | 1,000W | 15 min | 250Wh |
| Electric kettle | 1,500W | 10 min | 250Wh |
| WiFi router | 10W | 24 hours | 240Wh |
| Ceiling fan | 50W | 8 hours | 400Wh |
Note: Watts listed are averages. Check the power label on your specific devices for exact numbers.
Power Station Recommendations by Use Case
Camping / Weekend Trips (500-1,000Wh)
Typical load: Phone, laptop, small cooler, LED lights
Recommended capacity: 500-1,000Wh
Best picks: Jackery Explorer 500, EcoFlow River 2 Pro, Anker 535
CPAP / Medical Devices (500-700Wh)
Typical load: CPAP (without humidifier) for 2-3 nights
Recommended capacity: 500-700Wh
Best pick: Jackery Explorer 500 or 1000 v2 (CPAP mode)
Van Life / RV (1,500-3,000Wh)
Typical load: Mini fridge, lights, laptop, phone, occasional microwave
Recommended capacity: 2,000-3,000Wh
Best picks: Bluetti AC200L, EcoFlow Delta 2 (with extra battery)
Home Backup — Essentials Only (2,000-4,000Wh)
Typical load: Refrigerator, lights, router, phone charging, TV for 1-2 days
Recommended capacity: 2,000-4,000Wh
Best picks: EcoFlow Delta Pro, Bluetti AC300, Anker SOLIX F2000
Home Backup — Full House (5,000-10,000Wh+)
Typical load: Refrigerator, freezer, well pump, lights, TV, internet, microwave
Recommended capacity: 5,000-10,000Wh or more
Best picks: EcoFlow Delta Pro (x2 with Smart Home Panel), Bluetti AC500 + B300S
Important: Inverter Size Matters
Your power station must also be able to handle the starting surge of appliances. Large appliances like refrigerators, well pumps, and air conditioners require a surge current (2-5x normal wattage) when starting up. Always check the continuous AND surge output ratings.
| Appliance | Running Watts | Surge Watts (starting) |
|---|---|---|
| Refrigerator | 150-200W | 600-1,000W |
| Well pump (1/2 HP) | 750W | 2,000-3,000W |
| Window AC (5,000 BTU) | 500W | 1,500W |
| Sump pump | 800W | 1,500-2,000W |
Rule of Thumb
Multiply your daily Wh needs by the number of days you want backup, then add 20% buffer. If you plan to use solar panels for recharging, you can use a smaller battery since solar will replenish during the day.