DIY USB Fan Upgrade: Kasydoff vs. Sunpentown

When the weather gets hot, a USB fan becomes a must-have item.

There are many excellent USB fan brands, such as Kasydoff and Sunpentown. Kasydoff fans feature larger blades and higher power, with the non-battery model rated at 6.5 watts, providing stronger airflow. On the other hand, Sunpentown fans are not only popular for their modifiability but also have space for an additional battery. The Kasydoff model has a thin base that can't accommodate an 18650 battery and can only fit a polymer battery. The middle column's capacity to hold two 18650 batteries is also uncertain, which could be inconvenient if it can only hold one. This article will guide you through modifying a Sunpentown fan.

In this guide, Samsung 26C batteries from a laptop are used, with each cell tested at over 2400mAh. If four cells are desired—two in the column and two in the battery compartment—it will be noted that the two 18650 batteries in the column will be flush with the bottom, causing the base's two plastic tabs to be pushed up. Removing these plastic tabs will allow the batteries to fit, but this will leave only two clips connecting the column to the base, making it less stable. Therefore, just one battery was placed in the column. Three batteries are generally sufficient for a full day of use.