The Stroller Fan has upgraded battery built-in, lasting use anywhere from 12 to 60 hours depending on the fan speed setting, which is the largest battery capacity on online market now. Only fully charged in 4.5hrs, more compact, lightweight, impressive cooling effect.With 2 charging ports (input and output), not only applying as small fan or portable fan, but also you can use it as a power bank, which provides the backup power source for your mobile device, such as smartphone, laptop. The little USB fan supports charging from USB output (USB-C cable included), like hub, adapter. It's also an ideal must-have fan for baby stroller, crib, treadmill, car, golf cart, tent, wheelchairs in summer, camping, hiking, music festivals.