Usable capacity
Wh on the box is not the same as usable energy. We start with a realistic efficiency assumption and let you adjust it.
Independent planning tool · November 2026
How long will it actually run?
Pick an appliance and a power station. Get a realistic runtime estimate based on usable capacity, continuous output, and real-world load behavior.
No account. No sales pitch. Just the math and the specs.
28current models in the starter database
39appliances with wattage estimates
85%default usable-capacity assumption
0accounts required to use the tools
A calculator, not another listicle
Most buying guides say “bigger is better.” We show you where the limit actually is.
Continuous output
A station may have enough capacity but not enough watts. We flag loads that exceed continuous output or likely startup surge.
Duty cycle
Refrigerators and pumps cycle on and off. We account for average draw instead of assuming the compressor runs continuously.
The math is simple.
The hard part is getting the assumptions right. That is why each result shows the formula and the caveats.
Usable energyCapacity × efficiency
Average loadWatts × duty cycle
Estimated runtimeUsable energy ÷ average load
Popular ways to start
Pick the decision you are trying to make. Each tool is designed around a real use case.
Starter model snapshot
A small preview of the current database. Prices are reference values and can change.
| Brand | Model | Capacity | Output | Reference price |
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Important: runtime estimates are not guarantees. For medical devices, use manufacturer guidance and a backup plan. We do not recommend portable power stations as life-support equipment.
Popular planning guides
Start with the appliance or outage you are actually trying to solve.