Sizing tool

Runtime calculator

Estimate how long a power station will run a device. This is arithmetic, not a lab test — use it to shortlist sizes, then check the device’s actual draw.

How to read the result

Runtime hours ≈ (capacity × depth of discharge × efficiency) ÷ device watts.

  • Compressor fridges and pumps surge above their average wattage. Size continuous output with headroom.
  • CPAP draw jumps with heated humidifiers and heated hoses. Prefer the higher preset if you use either.
  • Cold weather reduces available capacity on many packs. Keep the unit indoors when you can.

Back to the comparison table to match a Wh target to current $/Wh.