Uniden XS1215 +1 - Manual (Page 8)

B. Install the Rechargeable Battery Pack into the Handset
The handset(s) are powered by rechargeable battery
packs. The battery recharges automatically when
the handset is placed in the charging cradle.
1) Press down on the handset battery case cover (use
the finger indention for a better grip) and slide the
cover downward to remove.
2) Plug the battery pack connector (red & black wires)
into the jack inside the battery compartment.
(The connector notches fit into the grooves of the
only one way.) Match the wire colors to the
polarity label in the battery compartment, connect
the battery and listen for a click to insure
connection.
3) Make sure you have a good connection by slightly
pulling on the battery wires. If the connection is
secure, the battery jack will remain in place.
4) Place the battery case cover back in the handset by
sliding it upwards until it clicks into place.
Repeat process for second handset
(XS1215+1 only).
Use only the Uniden
(BT-905) rechargeable
battery pack supplied
with your cordless
telephone.
[7]