The desktop charger can charge both the phone battery installed in the phone and an extra battery at the same time. The LED indicator turns red when the battery is charging. The indicator turns green when the battery charging is complete.
Note: You can insert and charge the phone with a battery installed alone. Or you can insert and charge the spare batter alone, or you can charge both the phone and the spare battery at the same time.
- Battery installed in the phone: 3.5 hours
- Both battery installed in the phone and the spare battery: 6 hours
- Battery Alone: 6 hours
*Use only Cisco recommended batteries with the Cisco Wireless IP Phone 7921G.