Portable Power Station Calculator

Determine the required battery capacity (Watt-hours), runtime for your appliances (CPAP, fridge, laptop, lights), and solar panel charging time.

1. Power Station Specifications

Preset Models / Custom

Battery Capacity (Wh)

AC Inverter Rating (Watts)

Inverter Efficiency (%) Typically 85% for AC, 92% for DC

Depth of Discharge Limit (%) Safety buffer (usually 85-90%)

2. Connected Loads & Appliances

Select Common Appliance Preset

Total Continuous Load (Watts)

Peak Startup Surge (Watts)

3. Solar Panel Recharge (Optional)

Solar Panel Wattage (Watts)

Peak Sun Hours / Day

Estimated Battery Runtime

Usable Energy: 783 Wh

Inverter Compatibility: OK

Total Load Power: 150 W

Solar Charge Time: --

Estimated Device Recharge Counts

Smartphone (12Wh) ~65 recharges

Laptop (60Wh) ~13 recharges

Drone Battery (40Wh) ~19 recharges

CPAP Machine (50W) ~15.6 hours

How to Calculate Portable Power Station Capacity & Runtime

Portable power stations (also called battery generators or solar generators) store energy in lithium-ion or LiFePO4 battery cells. To calculate actual usable runtime, you must factor in inverter conversion efficiency (usually 85%) and battery safety discharge thresholds (typically 90%).

Usable Energy (Wh) = Nominal Capacity (Wh) × Inverter Efficiency × Depth of Discharge Limit
Runtime (Hours) = Usable Energy (Wh) ÷ Continuous Connected Load (Watts)

Frequently Asked Questions

What is the difference between Wh and Watts?

Watts (W) measure instantaneous power speed or rate of energy draw, while Watt-hours (Wh) measure total energy capacity over time. A 100W appliance running for 2 hours consumes 200 Watt-hours.

Why does my power station run out faster than calculated?

Inverter overhead standby draw (usually 10-20W when turned on even without loads) and temperature conditions affect runtime. AC outlets incur higher conversion losses than built-in 12V DC or USB-C ports.