Panasonic KX-UDT131 Operating Instructions Manual page 13

If you replace the battery before the low battery warning
appears, the battery strength icon may display an
incorrect reading. In this case, use the handset as
normal with the new battery installed. To install the
battery, see "Battery Installation (Page 54)".
When the low battery warning is displayed, charge the
battery for about 3 hours. The battery strength icon will
then display the correct reading.
•
Please use only Panasonic batteries. For details,
consult your administrator or dealer.
•
There is a danger of explosion if the battery is
incorrectly replaced.
Document Version 2012-11
Important Information
Operating Instructions 13