Sony SPP-A974 Operating Instructions Manual page 11

Handset spare battery usage
As only one battery pack is supplied with this unit, it is necessary to
purchase an additional battery pack (optional) for use as a handset
spare battery pack.
BP-T23
SPARE BATTERY lamp
1
Open the battery compartment
lid of the base unit.
2
Insert the battery pack (with
contacts facing down) into the
battery compartment.
3
Close the battery compartment
lid.
The SPARE BATTERY lamp
lights up. Charge the battery
pack for more than 24 hours so
that the battery is fully charged.
The SPARE BATTERY lamp
remains lit even after charging
is completed.
US
11
Getting Started