What size portable power station do you need for the weekend?
Quick answer: Add up each device's watts × hours for one day, multiply by the number of days and by 1.2 for losses. A cabin using 1,100 Wh a day for 2 days needs about 2,640 Wh of battery. Runtime is battery Wh × 0.85 ÷ device watts.
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Weekend Cabin Power Example: 1,100 Wh Daily Load for Two NightsCabin at 1,100 Wh/day for two nights needs about 2,640 Wh battery after the 1.2 buffer. 300 W solar at 4.5 peaHow Much Battery Capacity Do You Need for a WeekendFor 1,200 Wh/day over three nights, plan about 4,320 Wh of battery after the 1.2 buffer.Calculate Runtime Hours from Any Power StationHow to calculate runtime hours from a power station's Wh rating and your load's wattage. Use the formula: battSize Solar Panels for a Weekend Power StationHow many solar watts do you need for a weekend power station? Use the panel W × peak sun hours × 0.75 formula Size a Generator for Cabin, RV, and Home-Backup SurgeHow to size a generator for weekend cabin, RV, and home-backup surge. Learn the surge formula, continuous wattCold-Weather Capacity Loss for Weekend Power StationsCold-weather capacity equals rated Wh times 0.85, so a 1,024 Wh station delivers only about 870 Wh usable when
The five formulas we use
| What | Formula |
|---|---|
| Runtime (hours) | battery Wh × 0.85 ÷ load W |
| Battery needed | daily Wh × days × 1.2 |
| Solar per day | panel W × peak sun hours × 0.75 |
| Surge | total running W − largest running W + largest starting W |
| Cold usable | rated Wh × 0.85 |
Every number on this site is an estimate. Figures from maker spec sheets and public data (EIA, NREL, CPSC) are cited on each page.