Power Station Runtime Calculator
Estimate how long a portable power station will run your 240V AC and 12V or USB loads.
A power station loses some energy turning its battery into 240V AC, and a little on its 12V and USB outputs. This allows for both, so you can see how long your loads might run. Everything is worked out in your browser. Nothing is saved or sent anywhere.
1. Your power station
Use the watt-hour (Wh) capacity from the label or manual.
Allows for the charge the unit keeps in reserve. Use the maker's figure if they give one.
2. Your loads
Add up the watts on each type of outlet. For things that cycle on and off, like a fridge, use the average draw. Enter 0 if you're not using that type.
Check the manual.
Used while the AC output is on. Check the manual for the no-load or idle figure.
3. Results
How it was worked out
What this does and doesn't tell you
- This is an idealised estimate for steady loads. Real runtime varies with temperature, battery age, the unit's own screens and fans, and how hard the loads work.
- It doesn't include any charging from solar, a car or the mains while the loads run.
- Check that each load is within the power station's output ratings, including start-up surge for things like fridges and power tools.
- For a 12V battery instead of a power station, use the Battery Runtime Calculator.
- Work on 240V AC wiring, including inverter outputs and mains inlets, must be done by a licensed electrician. For high-current DC gear such as inverters, DC-DC chargers and battery links, follow the maker's installation manual and have an auto electrician check your work if you're unsure.
Next steps
Work out what a fridge uses with the Fridge Power Draw Calculator, and how much solar would keep up with the Solar Panel Sizing Calculator. Still deciding? Read Power Station vs DIY Battery Box.