Battery charging troubleshooting for HDR headsets

"Battery basics
Use rechargeable NiMH AAA batteries (600–900 mA).
Do not use alkaline batteries in the charger. They can leak.
Lithium batteries are not supported by this charger, and should not be used.
What the charger lights mean
RS 120/135:
The charge light stays on when headphones are on the charger.
If the light never comes on, or goes out after a few minutes, there is a charge fault.
RS 120-W
Charge LED is red when charging
Charge LED goes out when fully charged (or if no headphones are on the charger)
RS 165/175/185/195:
The Charge LED turns green when fully charged
When batteries are replaced, charge LED calibration may take a few days
Use the headphones as normal, and the LEDs will sync within 72 hours
If the charger light is blinking, there is a charging fault.
Common causes
Not using NiMH AAA batteries.
Batteries not fully inserted or not aligned correctly. The flat side should face the spring.
Cushions not fully seated, so cups don't touch the charger pins.
Simple steps to fix (try these one by one)
1. Turn off the headphones. Open the cushion by turning left and lifting off.
2. Remove the batteries. Reinsert them, making sure the flat side faces the spring.
3. Make sure the adjustable headband is fully closed and cups sit evenly on the charger.
4. Swap the batteries: put the left battery in the right cup, and the right battery in the left cup. See if charging improves.
5. Clean the contact points on the headband and in the battery compartment with a pencil eraser.
6. If you still have trouble, unplug the transmitter for 15 minutes, then plug back in.
7. If the problem continues, replace the NiMH AAA batteries with new ones and try again.
Extra tips
If the cushion is hard to open, rotate the cover a bit more and try again.
Make sure the headset is completely off before opening."