Portable Power Station Runtime Calculator
Estimate how long a portable power station may run a device. Enter the battery capacity, average device load, efficiency and reserve. The result is a planning estimate, not a guaranteed runtime.
Estimated runtime
9.79 hours
- Usable energy after efficiency
- 652.8Wh
- Energy after reserve
- 587.5Wh
- Formula
- (Wh x efficiency x reserve factor) / watts
Actual runtime changes with load cycling, inverter behavior, battery age, temperature, cable losses and the output type used.
How the runtime estimate works
The basic calculation is battery capacity in Wh x efficiency x remaining reserve / average load in W. Capacity estimates available energy. Output wattage is a separate limit: the station must also support the device's running watts and startup demand.
Use average load for devices that cycle
Refrigerators, coolers, pumps and some CPAP configurations do not draw one fixed wattage continuously. A measured average over time gives a better estimate than using only the highest label value. Always check startup demand separately.
FlashFish capacity examples
| Model | Capacity | Rated output | Product page |
|---|---|---|---|
| A101 | 97.68Wh | 120W | View A101 |
| E200 | 151Wh | 200W | View E200 |
| E103 | 179.2Wh | 300W | View E103 |
| T300PRO | 230Wh | 300W | View T300PRO |
| T1200S | 768Wh | 1200W | View T1200S |
| T2000 | 1536Wh | 2000W | View T2000 |
Frequently asked questions
Why is the result lower than capacity divided by watts?
The calculator includes adjustable conversion efficiency and reserve. Real systems lose some energy through conversion, electronics, cables and standby operation.
Does a runtime result mean the device is compatible?
No. Check rated output, peak or startup demand, outlet type, voltage, frequency and device instructions separately.
Can I use this estimate for medical or life-critical equipment?
Do not use a general calculator as the only basis for life-critical planning. Follow the equipment manufacturer and qualified professional guidance and maintain an appropriate backup plan.
Does solar charging extend runtime?
It can, but solar input varies with weather, season, shade, panel angle and station input limits. Do not add rated panel watts as if they were constant all day.
