Panasonic KX-TGP600G Operating Instructions Manual page 96

Installation and Setup
96
R The charge indicator will turn off when the batteries are fully charged.
R If the batteries are already fully charged and the handset is placed in the
charger while the power is off, the charge indicator will turn on and then turn
off.
R Battery charging will begin about 3 seconds after placing the handset in the
charger when the power is off.
For more information about charging batteries, see "Battery Information
(KX-TPA60 only)", Page 12.
R It is normal for the handset and charger to feel warm while the batteries are
charging.
R Keep devices sensitive to magnetic fields away from the charger.
R Use only the included charger.