20000mAh Rechargeable Battery Operated Box Fan: This small box fan offers up to 55hrs duration thanks to its built-in 20000mAh rechargeable battery. It takes 8hrs to be full charged with 5V/3A ...

For users that need to cool off a big room, a larger box fan is best. However, for a smaller bedroom or an office space, a small box fan will get the job done just as well and at a lower price point.