Samsung Intensity User Manual page 11

Installing the Battery
Lift the battery cover from the top end of the handset.
1.
Insert the top end of the battery into the phone housing
2.
using the directional arrow printed on the battery. The gold
contacts at the battery end must align with contacts on the
phone. Push bottom end of the battery down until it snaps
into place.
6
Align the battery cover with the handset and push down
3.
until it snaps into place.