Panasonic KX-TCD430GC Service Manual page 6

Clean the charge contacts of the handset and base unit with a soft, dry cloth, otherwise the
batteries may not charge properly. Clean if the unit is exposed to grease, dust or high humidity.
If the handset is turned off, it will be turned on automatically when it is placed on the base unit.
Note for Service:
The battery strength may not be indicated correctly if the battery is disconnected and connected
again, even after it is fully charged.
In that case, by recharging the battery as mentioned above, you will get a correct indication of
the battery strength.
4.3. Battery Life
After your Panasonic batteries are fully charged, you can expect the following performance:
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