Portable battery planning
Portable Power Station Calculator
Estimate how long a portable power station can run your appliances, or calculate the nominal capacity needed for a target runtime. The model separates average energy use from connected output requirements.
Estimate portable power station performance
How long will a portable power station run?
The calculator starts with the station's rated battery capacity, reserve, battery health and AC efficiency, then divides estimated delivered AC energy by the average load.
Nominal capacity versus delivered AC energy
A station's rated Wh capacity is not the same as the energy available at its AC outlets. Reserve, battery health and inverter losses reduce the estimated delivered AC energy.
Portable power station capability chart (What can it run?)
Estimated runtime across common portable power station capacities (e.g. Jackery, EcoFlow, Bluetti, Anker) assuming 10% reserve and 88% AC inverter efficiency:
| Device / Appliance | Average Power | 300 Wh Station (~240 Usable Wh) | 500 Wh Station (~400 Usable Wh) | 1,000 Wh Station (~800 Usable Wh) | 2,000 Wh Station (~1,600 Usable Wh) |
|---|---|---|---|---|---|
| Smartphones & Tablets (15W USB-C) | 15 W | ~16 charges | ~27 charges | ~53 charges | ~107 charges |
| Laptop (65W USB-PD) | 45 W avg | ~5.3 hours | ~8.9 hours | ~17.8 hours | ~35.6 hours |
| 12V 45L Portable Camping Fridge | 20 W avg (cycling) | ~12 hours | ~20 hours | ~40 hours (1.7 days) | ~80 hours (3.3 days) |
| CPAP Machine (no heated humidifier) | 35 W | ~6.9 hours | ~11.4 hours | ~22.9 hours (2.8 nights) | ~45.7 hours (5.7 nights) |
| Starlink Satellite Dish | 60 W | ~4.0 hours | ~6.7 hours | ~13.3 hours | ~26.7 hours |
| Full-Size Home Refrigerator | 150 W avg (450W surge) | Inverter limit check | ~2.7 hours | ~5.3 hours | ~10.7 hours |
Average load, running watts and startup demand
Equipment duty cycles affect average energy use, while continuous output checks use the listed running watts. Startup checks use only explicit startup values and do not infer universal motor-surge multipliers.
Power station capacity for a desired runtime
Capacity mode calculates an energy requirement from average load and target runtime. It does not guarantee that a station has enough continuous or surge output for the connected equipment.
Worked example
A 1,024 Wh station with 5% reserve, 100% battery health and 90% AC efficiency provides an estimated 875.52 Wh of delivered AC energy. At a 100 W load, that is approximately 8 hours 45 minutes.
Portable Power Station Runtime & Capacity Formulas
Calculates operational hours from battery storage and validates whether continuous and surge wattage demand satisfy the station's built-in inverter limits.
Runtime (hours) = (Station_Wh × Usable_Window × Health × Inverter_Eff) / Load_WattsVariable Definitions
Station_WhRated Battery Energy(Wh)- Nominal lithium battery capacity of the power station (e.g. 512 Wh, 1,024 Wh, 2,048 Wh).
Usable_WindowUsable SOC Share(fraction)- Available capacity above internal BMS cutoff (typically 90%–95%).
Inverter_EffPure Sine Wave Inverter Efficiency(fraction)- Internal DC-to-AC conversion efficiency (typically 85%–90%).
Load_WattsAverage Connected Load(W)- Running watts × duty cycle.
Engineering Notes & Standards
- Required Capacity Mode: Station_Wh = (Load_Watts × Desired_Hours × (1 + Margin)) / (Usable_Window × Inverter_Eff).
- Power check: Running Watts ≤ Continuous Inverter Limit, and Startup Surge Watts ≤ Peak Surge Limit.
Frequently Asked Questions (FAQ)
How long will a 1,000 Wh portable power station run a refrigerator?
Can a portable power station run high-wattage appliances like a microwave or coffee maker?
What is the difference between power station Wh capacity and continuous Watt rating?
Why does my 500Wh power station only deliver around 400Wh to AC appliances?
Related calculators
Use the Battery Runtime Calculator for a general battery runtime estimate or the Electricity Usage Calculator for household appliance energy planning.