Plug into external power when convenient to save the batteries in a Beam n Read Hands-Free Light for when portability is needed or during power outages. Saves $$ too. Kit includes a 6 foot Beam n Read-to-USB Cable plus a 6 foot USB Extension Cable to let you work 12 feet from the power source. Plug into the included USB/AC adapter or a USB car adapter, the USB socket by an airline seat or in a hotel room, the USB port on a computer, the USB adapter/charger for other electronic devices, etc. The USB Power Kit enables access to external power, it does not recharge batteries.