Patent ID: 7012402

Claim:
A battery recharging circuit in a wireless microphone comprising: a pair of terminals on the microphone for connecting to an external power supply; a battery charging circuit in the microphone connected to the pair of terminals for charging a battery in the microphone; a microcontroller in the microphone for controlling the battery charging circuit; means for measuring unloaded and loaded voltages across the battery; said microcontroller including battery type determining means for determining from the measured voltages whether the battery is a rechargeable or non-rechargeable battery, and means for preventing recharging the battery if the battery is not determined to be a rechargeable type of battery; and a discharge circuit operated by the microcontroller for discharging the battery; said microcontroller including means responsive to a finding of a battery in an indeterminate charged state wherein unloaded and loaded voltage measurements cannot be reliably used to distinguish rechargeable and non-rechargeable batteries to operate said discharge circuit for discharging the battery to a lower charged state where unloaded and loaded voltage measurements can be reliably used to distinguish rechargeable and non-rechargeable batteries.