Rechargeable fans are devices that are designed to cool off a person, object or area using replenishable battery power. These devices are often used for personal cooling and can even be installed in safety helmets, although they also are found in applications such as composting toilets. Most of these fans have built-in battery packs, although it is possible to turn a regular fan into a rechargeable fan with the right type of batteries. It also is possible for a single rechargeable fan to operate from many sources of electricity, including a built-in battery pack, regular removable batteries or an alternating current (AC) adapter. Some rechargeable fans also include photovoltaic (PV) solar cells, which can provide an alternate source of power to charge the batteries.
There are many types of rechargeable fans that can be used in a variety of applications, although they all share a common source of power. Most of these devices have built-in power packs that might be removable or even recyclable depending on the particular design. In some cases, a rechargeable fan will have no alternate power sources and will include a battery pack that is not serviceable by the user. Other devices include an option for the fan to operate using the same AC adapter that charges the battery pack or even have space for regular batteries to be inserted. Rechargeable fans that have multiple power sources sometimes include a feature that automatically selects the best one, depending on what is available.
In addition to a rechargeable battery pack and an AC adapter, some rechargeable fans also offer additional power sources. One option that is sometimes available is a solar charger, which can either power the fan outright or charge the batteries when the unit is not in use. Some fans also can be plugged into the universal serial bus (USB) port of a computer to receive a charge. Most nickel-cadmium (NiCd) and nickel-metal hydride (NiMH) batteries can be also be used to turn a regular-battery operated fan into a rechargeable fan.
Many rechargeable fans are designed for personal use, either as semi-portable desk units or fully portable devices that can be easily carried in a pocket, briefcase or purse. These personal units sometimes include additional features, such as radios, flashlights and other electronic components. This type of device is sometimes solar powered or includes hand cranks, so a multi-function rechargeable fan will often be include in a well-stocked disaster kit.
There also are other areas in which rechargeable fans can be used. These devices are sometimes placed inside safety helmets to provide increased comfort to workers without reducing safety. Other applications that often makes use of rechargeable fans are composting toilets and other devices that have vents that need to move a lot of air but do not have access to AC power.