How to Calculate Portable Power Station Runtime

How to Calculate Portable Power Station Runtime
One of the most common questions when choosing a portable power station is:
“How long will it run my device?”
To estimate runtime, you need two basic values:
Power station battery capacity in WhPower consumption of the connected device in WThese values can be used to calculate approximate operating time.
Portable Power Station Runtime Formula
Solar Wise uses an 85% efficiency factor for practical runtime calculations.
The approximate formula is:
Battery capacity (Wh) × 0.85 ÷ device consumption (W) = runtime in hours
For example, with a 288Wh battery and a constant 60W load:
288 × 0.85 ÷ 60 = 4.08 hours
With a 576Wh battery and the same 60W load:
576 × 0.85 ÷ 60 = 8.16 hours
These figures are estimates. Actual runtime may vary depending on the connected device and operating conditions.
Why Isn't the Entire Battery Capacity Available?
A purely theoretical calculation could divide battery capacity directly by device wattage.
In real-world operation, however, energy conversion involves losses. AC output, electronic circuits and power management all consume some energy.
For this reason, Solar Wise practical runtime calculations use an 85% efficiency factor.
What Is the Difference Between Watts and Watt-Hours?
Understanding the difference between W and Wh is important for calculating runtime.
Watts (W) describe electrical power consumption.
Watt-hours (Wh) describe the amount of energy stored in the battery.
For example:
Solar Wise E300LFP:
288Wh battery capacity
600W continuous pure sine wave AC output
Solar Wise E500LFP:
576Wh battery capacity
600W continuous pure sine wave AC output
Both models provide the same continuous AC output rating, but the E500LFP stores more energy and can therefore provide longer runtime under the same load conditions.
Learn more about watts and watt-hours:
https://solarwise.com.tr/blog/watt-wh-arasindaki-fark
How Long Can the E300LFP Run a 60W Device?
The Solar Wise E300LFP has a 288Wh battery.
For a constant 60W load:
288 × 0.85 ÷ 60 = 4.08 hours
The estimated runtime is approximately 4.08 hours.
E300LFP technical specifications:
https://solarwise.com.tr/urun/e300lfp
How Long Can the E500LFP Run a 60W Device?
The Solar Wise E500LFP has a 576Wh battery.
For the same constant 60W load:
576 × 0.85 ÷ 60 = 8.16 hours
The estimated runtime is approximately 8.16 hours.
E500LFP technical specifications:
https://solarwise.com.tr/urun/e500lfp
Where Can You Find a Device's Wattage?
Before calculating runtime, determine the power consumption of the device you want to use.
This information can usually be found:
On the device's technical labelOn its power adapterIn the user manualOn the manufacturer's specifications pageDoes a Device Always Consume the Same Wattage?
Not necessarily.
The power consumption of some electronics changes during operation.
A laptop, for example, may consume different amounts of power depending on processor load, screen brightness and battery charging status.
A compressor refrigerator also cycles on and off, meaning its instantaneous power consumption may differ from its average energy consumption.
For this reason, calculations based on a fixed wattage should be treated as estimates.
For more information about refrigerator runtime:
https://solarwise.com.tr/blog/guc-istasyonu-buzdolabi-kac-saat-calistirir
How Do You Calculate Runtime for Multiple Devices?
When several devices are used simultaneously, add their power consumption together.
For example:
Router: 10W
Laptop: 50W
Total load:
10W + 50W = 60W
For an E500LFP:
576 × 0.85 ÷ 60 = 8.16 hours
Actual runtime may vary because device consumption can change during operation.
Can Runtime Be Calculated from the 600W Rating Alone?
No.
The 600W figure describes the power station's output capability, not the amount of energy stored in its battery.
Battery capacity in Wh is also required to estimate runtime.
For example:
E300LFP: 288Wh / 600W
E500LFP: 576Wh / 600W
Both provide 600W continuous AC output, but their available energy capacity is different.
Learn more about what a 600W portable power station can run:
https://solarwise.com.tr/blog/600w-guc-istasyonu-neleri-calistirir
What Factors Affect Real-World Runtime?
Actual runtime can differ from the calculated estimate due to factors including:
Actual device power consumptionAC or DC output useNumber of connected devicesAmbient temperatureDevice operating patternMotor or compressor cyclingCurrent battery charge levelThe calculated figure should therefore be considered an approximate runtime estimate.
Conclusion
Portable power station runtime can be estimated by considering battery capacity and the power consumption of the connected device.
Solar Wise practical calculation:
Battery capacity (Wh) × 0.85 ÷ device consumption (W)
Example:
E300LFP / 288Wh / 60W load: approximately 4.08 hours
E500LFP / 576Wh / 60W load: approximately 8.16 hours
Actual runtime may vary depending on device consumption and operating conditions.
Solar Wise E300LFP:
https://solarwise.com.tr/urun/e300lfp
Solar Wise E500LFP:
https://solarwise.com.tr/urun/e500lfp