BCD436HP Fully charged batteries loosing charge while listing to Radio with USB power

Having a problem with the radio. Scanner charges batteries and the batteries last for a good 8 hours with no issues.



When batteries are fully charged and I leave the radio on and plugged into the USB power source for a couple of weeks at a time 24x7 - when I unplug the USB the batteries are dead,



Any known issues of power drainage to the batteries while being used with the external power source.



Thanks.

BCD436HP Fully charged batteries loosing charge while listing to Radio with USB power