When there are one week of battery life left on a Drive, an icon of a battery that is almost empty will appear on the screen. When there is a day's battery time left, an empty battery will be show on the screen, and then it must be charged.
You charge the Drive by plugging it into a UBS charger. It can be from a computer or a regular USB charger, which many phones, tablets and other electrical devices use. You can use the included cable to connect your Drive to the USB charger, or you can use any other UBS to Micro USB cable.
When properly charged, there will be an icon on the Drive screen with a lightning bolt in the , and when fully charged, the battery on the Drive screen will be fully charged (if the screen is turned on during charging), and you can take it out of the charger and put it back in the car again.