The Red LED Light on the Charger Doesn't Turn Off
The MDR-RF995RK headphones require seven to nine hours to fully charge. During this time, the red LED on the transmitter remains lit. Every time the headphones are removed and placed back on the transmitter, the red LED will light up for another seven to nine hour cycle.
Note: Even a gentle bump on the headphones while they're on the transmitter can cause one or both of the contact pins to move and restart the charging cycle.