OUPES Portable Power Station Run Time Calculator

Estimated runtime is calculated using the selected power station’s battery capacity and the total wattage of the connected appliances.

A simplified formula is:

Runtime (hours) = Usable battery capacity (Wh) ÷ Total appliance load (W)

The result is an estimate. Actual runtime may be lower because of inverter loss, standby consumption, temperature, battery condition, and changes in appliance power usage.

The calculator provides an estimate based on the wattage entered. Actual runtime can vary because appliances do not always consume the same amount of power.

Temperature, battery age, AC inverter efficiency, power station settings, appliance startup power, and other connected devices may also affect runtime. For critical applications, allow an additional safety margin rather than relying on the calculated time alone.

Enter the appliance’s normal running wattage, which can usually be found on its label, power adapter, user manual, or manufacturer’s website.

If the label only shows volts and amps, you can estimate wattage using:

Watts = Volts × Amps

Some appliances may consume more or less power during normal operation, so a plug-in power meter can provide a more accurate measurement.

Battery capacity, measured in watt-hours (Wh), determines approximately how long a power station can run your devices.

Output power, measured in watts (W), determines whether the power station can operate those devices.

For example, a larger battery may provide longer runtime, but the power station must still have enough continuous and surge output to start and run the appliance safely.

The runtime calculation is primarily based on normal running wattage. However, refrigerators, air conditioners, pumps, compressors, power tools, and other motor-driven appliances may require much higher power for a few seconds when starting.

Before choosing a power station, confirm that both its continuous output and surge output meet the appliance’s requirements.

Add the running wattage of every appliance that will operate at the same time, including the quantity of each device.

For example:

2 lights at 10W each + 1 router at 25W + 1 laptop at 60W = 105W total load.

Enter the combined wattage into the calculator. Remember that any additional device connected later will reduce the actual runtime.

Refrigerators and air conditioners cycle on and off to maintain a target temperature. Their compressors may use high power while running and very little power while idle.

Because cycling frequency depends on room temperature, appliance efficiency, thermostat settings, insulation, and how often the door is opened, actual runtime may differ significantly from a calculation based only on rated wattage.

Yes. A compatible extra battery increases the total stored energy of the system and can extend runtime.

For example, increasing total system capacity from 2,048Wh to 4,096Wh may provide approximately twice the runtime under similar conditions. However, an extra battery does not necessarily increase the power station’s AC output, so appliance wattage limits still apply.

Unless otherwise stated, the estimated runtime is based on stored battery energy and does not include additional solar charging during use.

Solar panels may extend runtime when they generate power, but actual solar input depends on sunlight, weather, panel angle, temperature, shading, and the power station’s maximum solar input. Solar panel rated wattage is not guaranteed continuous charging wattage.

The calculator may help estimate energy requirements, but it should not be used as the only basis for medical backup planning.

Actual medical-device consumption may vary by settings, accessories, humidifiers, and operating mode. Confirm the device’s power requirements with its manufacturer and maintain a medically appropriate backup plan for critical equipment.

For non-critical everyday use, selecting a power station with at least 15–20% more estimated capacity than your calculation can help account for conversion loss and changing power consumption.

For emergency, medical, refrigeration, or other critical applications, consider a larger reserve based on the importance of the device and the expected duration of the outage.

You can manually enter the appliance’s running wattage in the calculator.

Check the appliance label, user manual, power adapter, or manufacturer’s specifications. For appliances with motors, compressors, pumps, or heating elements, also verify startup and maximum power before connecting them to a portable power station.