Portable battery planning
Portable Power Station Calculator
Estimate how long a portable power station (Jackery, EcoFlow, Bluetti, Anker) will run your devices, or calculate the watt-hour capacity you need for camping and emergency backup.
Estimate portable power station performance
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How to Calculate Power Station Runtime & Sizing
- Select Power Station Capacity: Choose standard sizes (256Wh, 512Wh, 1000Wh, 2048Wh) or enter custom watt-hours.
- Add Connected Devices: Add laptops, camping fridges, CPAP machines, or lights with realistic running watts and duty cycles.
- Verify Inverter Limits: Ensure device running watts and startup surges do not exceed the station's continuous AC inverter rating.
- Review Operating Duration: View calculated operating hours and delivered AC energy available on a full charge.
Portable Power Station Capability Chart (What Can It Run?)
Estimated runtime across common portable power station capacities assuming canonical planning assumptions of 90% usable capacity (10% reserve) and 88% AC inverter efficiency (delivered AC Wh = Station Wh × 0.792):
| Device / Appliance | Average Power | 300 Wh Station (~238 Delivered AC Wh) | 500 Wh Station (~396 Delivered AC Wh) | 1,000 Wh Station (~792 Delivered AC Wh) | 2,000 Wh Station (~1,584 Delivered AC Wh) |
|---|---|---|---|---|---|
| Smartphones (~12 Wh battery, ~90% DC charging) | 15 W max | ~20 recharges | ~33 recharges | ~67 recharges | ~135 recharges |
| Laptop (USB-PD) | 45 W avg | ~5.3 hours | ~8.8 hours | ~17.6 hours | ~35.2 hours |
| 12V 45L Portable Camping Fridge | 20 W avg (cycling) | ~11.9 hours | ~19.8 hours | ~39.6 hours | ~79.2 hours |
| CPAP Machine (no heated humidifier) | 35 W | ~6.8 hours | ~11.3 hours | ~22.6 hours | ~45.3 hours |
| Starlink Satellite Terminal | 60 W | ~4.0 hours | ~6.6 hours | ~13.2 hours | ~26.4 hours |
| Full-Size Home Refrigerator | 150 W avg (450W surge) | Inverter check (~1.6h) | ~2.6 hours | ~5.3 hours | ~10.6 hours |
*Note: Delivered AC energy equals Station Wh × 90% usable × 88% inverter conversion efficiency. Smartphone recharges assume a 12 Wh phone battery with 90% DC charging efficiency. Refrigerator runtime assumes station continuous output ≥ 150W and peak surge capacity ≥ 450W.*
Portable Power Station Runtime & Capacity Formulas
Calculates operating hours from battery storage and verifies whether continuous and surge wattage demand satisfy the station's built-in inverter limits.
Variable Definitions
Station_WhRated Battery Energy(Wh)- Nominal lithium battery capacity of the power station (e.g. 512 Wh, 1,000 Wh, 2,048 Wh).
Usable_FactorUsable Capacity Factor(fraction)- Available capacity fraction above internal BMS reserve cutoff (typically 90%–95%).
Battery_HealthState of Health(fraction)- Available battery capacity relative to original factory nominal rating (typically 80%–100%).
Inverter_EfficiencyPure Sine Wave Inverter Efficiency(fraction)- Internal DC-to-AC conversion efficiency (typically 85%–90%).
Load_WAverage Connected Load(W)- Running watts × duty cycle.
Calculation Notes
- Required Capacity Mode: Required_Station_Wh = (Load_W × Desired_Runtime_h × (1 + Margin)) / (Usable_Factor × Battery_Health × Inverter_Efficiency).
- Power Check: Running Watts ≤ Continuous Inverter Rating, and Startup Surge Watts ≤ Peak Surge Limit.
Frequently Asked Questions (FAQ)
How long will a 1,000Wh portable power station run a refrigerator?
Runtime depends on the refrigerator's average power draw, compressor duty cycle, ambient temperature, battery reserve cutoff, and inverter conversion efficiency. For example, a refrigerator drawing 150W with a 33.3% duty cycle averages 50W. On a 1,000Wh power station with 90% usable capacity (10% reserve) and 88% AC inverter efficiency, delivered AC energy is 792 Wh (1,000 × 0.90 × 0.88), providing approximately 15.8 hours of runtime (792 ÷ 50W). In addition to runtime, ensure the power station's continuous output exceeds 150W and peak surge capacity handles compressor startup (~400W–600W).
Why does my 500Wh power station not deliver a full 500 watt-hours?
Portable power stations cannot deliver 100% of nominal battery capacity at the AC outlets due to two loss factors: internal battery reserve cutoff (typically 5%–10% retained by the BMS to protect lithium cells from over-discharge) and DC-to-AC pure sine wave inverter conversion losses (typically 10%–15% loss, or 85%–90% efficiency). On a 500Wh station with 90% usable capacity and 88% inverter efficiency, expected AC outlet energy is approximately 396 Wh (500 × 0.90 × 0.88).
What size power station do I need for camping?
Required power station capacity depends on your total daily device watt-hours, operating hours, appliance duty cycles, desired reserve, and conversion losses. For example, running a 12V camping fridge (20W average × 24h = 480 Wh) and charging two phones (24 Wh) requires ~504 Wh delivered. Factoring in 90% usable capacity and 88% efficiency, a power station of at least 636 Wh nominal capacity is needed (504 ÷ (0.90 × 0.88)).
Can a portable power station run a coffee maker or microwave?
Running high-wattage heating appliances depends on the power station's inverter continuous output (W) and surge capability, not its energy capacity (Wh). A 1,000W coffee maker or 1,200W microwave requires a power station with an inverter rated for at least 1,200W–1,500W continuous pure sine wave output, regardless of whether the battery capacity is 500Wh, 1,000Wh, or 2,000Wh.