QuietComfort® 3 headphones are powered by a rechargeable lithium-ion battery. Before using the battery for the first time, make sure it is fully charged to ensure optimal battery life.
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:
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.
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. Make sure the battery is pushed all the way in until it is flush with the earcup
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.