Uniden IGO CAM 820 Owner's Manual page 9

Battery Information
Although primarily designed for in-car use, the unit can operate from its built-
in 800mAh battery for up to 35 minutes.
Please note, the power usage would depend on day/night recording and
resolution setting.
The unit will charge the battery whenever power is detected through the USB
port. When the unit is being charged, the left Red LED will glow. The LED will
turn off when the unit has been charged completely.
The unit will take about 2 hours to charge completely.
Battery Alert
The image given below indicates the battery level at different stages.
Full
UNIDEN iGO CAM 820
Half full
9
Low
Empty
Vehicle Recorder