Sony DSLR-A390 Instruction Manual page 14

Preparingthe battery pack
When using the camera for the first time, be sure to charge the NP-FH50
"InfoLITHIUM" battery pack (supplied).
The "InfoLITHIUM" battery pack call be charged even when it has not
been fully depleted.
It call also be used when it has not been fully charged.
1
Insertthebattery packon the
battery charger.
Push the battery pack until it clicks.
14