The length of time a portable power station can run depends on several factors, such as the capacity of the power station's battery, the power draw of the devices being powered, and the efficiency of the power station's inverter. As an example, a portable power station with a 100Ah battery capacity and an inverter efficiency of 90% could run a 100W device for about 27 hours. However, this is just an estimate and the actual run time could vary depending on the specific model and usage conditions.