Panasonic EASA-PHONE KX-T3720 Operating Instructions Manual page 15

Charging the portable unit
Charge the battery of the portable unit for about 10 hours before
initial use or if the BATT LOW/PROG indicator on the portable unit
flashes.
Place the portable
unit on the cradle.
You can use the unit before the 10 hours are up.
But be sure to put the portable unit on the cradle so it can
continue charging.
@ Even when the BATT LOW/PROG indicator flashes, the portable unit
will still function for a short time.
@ |f you want the telephone to ring while charging, set the POWER/
RINGER switch on the portable unit to "ON".
@ While the POWER/RINGER switch is in the "OFF" position, the
telephone will not ring. Other phones connected to the same line
'will work normally.
® Clean the battery charge contacts with a soft cloth about once a
month, otherwise the portable unit may not be charged properly.
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