Portable energy
How to choose a portable power station
Understand watt hours, output, charging speed, battery chemistry and real usable capacity.
Published 2 September 2026 · General buying information
01
Capacity and output solve different problems
Capacity in watt hours estimates how much energy the battery stores. Output in watts tells you how much power it can deliver at one time. A unit can have enough capacity for an appliance but still lack the output needed to start it.
- List the running watts of each device
- Check starting or surge power
- Allow for conversion losses
02
Estimate usable run time
A simple estimate is battery watt hours multiplied by an efficiency allowance, divided by the device wattage. Real results vary with temperature, inverter load, battery protection and the way the appliance cycles.
03
Check every charging method
Compare wall charging, solar input, car charging and USB-C input. Solar panel wattage is not the same as the power the station can accept, so check the station's maximum solar input and voltage range.
04
Battery cycle figures need context
Manufacturers usually state the number of full cycles before the battery reaches a percentage of its original capacity. Compare the cycle count and the remaining capacity percentage together.