QuietComfort 3 headphones are powered by a rechargeable lithium-ion battery. Before using the battery for the first time, be sure to fully charge it to ensure optimal battery life.
Charging the battery
Initial charging time for a new battery is approximately two hours. After that, charging time varies, depending on the battery charge state. To charge the battery, follow these steps:
Insert the battery into the charger
Swing the plug prongs out of the charger body
Plug the charger into a live AC (mains) outlet
An indicator light comes on when the battery is charging properly and turns off when the battery is fully charged. If the red LED on the charger flashes, the battery may not be charging properly.
After charging, unplug the battery charger and remove the battery.
Note: Do not store a battery in the charger. Doing so will diminish the charged state of the battery over time and may permanently reduce the capacity of the charger.
Installing the battery
Be sure to fully charge the battery before first use. To install a charged battery, follow these steps:
- Make sure the headphones' power switch is off
- Hold the right earcup, as shown
- Insert the battery into the compartment. Be sure to push the battery all the way in until it is flush with the earcup
Removing the battery for charging
The On/Off light on your headphones will flash when approximately four hours of battery life remain. This indicates when the battery will need to be recharged. To remove the battery so you can recharge it, follow these steps:
- Make sure the headphones power switch is off
- Hold the right earcup, as shown in the illustration under "Installing the battery"
- Lift the battery straight up and out of the battery compartment
A fully charged battery provides approximately 20 hours of use. Under typical conditions, the battery should last for approximately 500 charge cycles. Replace the battery when it no longer provides adequate power after charging.