Power station modelEcoFlow DELTA 2
Battery capacity (Wh): 1024 WhContinuous output rating (W): 1800 WSurge output rating (W): 2700 W
portable power station runtime calculator
Portable Power Station Runtime Calculator
Use this calculator when you know the battery size and the device wattage, or when you want a quick sanity check before an outage or trip.
Calculator
Start with a quick estimate, then switch to Advanced if you need multiple devices, startup surge, battery health, or cold-weather loss.
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Power station model
Output path
Estimated runtime
13h 3mThis setup has comfortable headroom for overnight use, assuming the wattage estimate is realistic.
Usable energy783 Wh
Average load60 W
Running watts60 W
Max surgen/a
Conservative8h 10m
Estimated13h 3m
Optimistic16h 13m
Conservative assumes harder conditions; optimistic assumes favorable conditions.
- 1024 Wh nominal battery capacity
- AC inverter output path
- 85% conversion efficiency
- 10% reserve kept unused
- 60 W average load from 1 load
- 100% battery health
- 0% temperature loss
- This is an estimate. Real runtime changes with load, temperature, battery age, AC/DC output, and device behavior.
Source-Backed Next Steps
Smallest matching recordJackery Explorer 600 v2Best for
Calculate how long a station will run a known load.
Runtime worked example
A 1,024 Wh station at 85% AC efficiency with a 10% reserve leaves about 783 Wh usable. At a steady 60 W load, that works out to 13h 3m.
Change first
- Change watts first when you have a watt-meter reading; change efficiency when switching between AC and DC output paths.
- Check startup surge for motors, compressors, and pumps.
- Use measured watts for outage or medical-adjacent planning.
This calculator gives a planning estimate. Treat the result as a starting point, then refine it with measured watts, the device manual, and the station's current output limits.
Verify your watts
- Check the device label for running watts or input amps and volts.
- Use a plug-in watt meter for AC loads when the result matters.
- For cycling loads, measure long enough to capture on/off behavior.
Check output path
- AC inverter loads usually lose more energy than direct DC loads.
- Keep reserve for cold weather, battery age, and load changes.
- Do not treat label capacity as fully usable watt-hours.
Related Calculators
Use the related tools when charging, sizing, surge, or power path changes the answer.
FAQ
These answers keep the estimate grounded in assumptions instead of pretending runtime is exact.
How do you calculate portable power station runtime?
Use usable watt-hours divided by average load watts. For AC loads, a practical first-pass formula is battery Wh x efficiency x reserve factor divided by device watts.
Why is real runtime lower than the label capacity?
Battery label capacity is nominal. Inverter losses, DC conversion losses, reserve settings, cold weather, battery age, and changing device loads all reduce real runtime.
What efficiency should I use for AC devices?
Use 80% to 90% for most AC inverter loads unless you have measured data. The default calculator value is 85%.
What efficiency should I use for DC devices?
DC loads can often do better than AC because the inverter stays off. Use 88% to 95% only when the voltage path is appropriate and the device is stable.
Is a 1000Wh station really one kilowatt-hour usable?
Not for AC loads. A 1000Wh station at 85% efficiency with a 10% reserve gives about 765Wh usable for the load.
Should I reserve 20% battery?
A 10% to 20% reserve is a practical buffer for uncertainty, startup spikes, and avoiding a completely empty station during an outage.
Why should I measure with a watt meter?
Device labels are often maximum ratings. A watt meter shows real average draw and makes runtime estimates much more reliable.