NEC 750C - Manual (Page 9)

Quick Start 1-3
Installing the Batteries
1. Slide the main battery cover lock to the unlocked posi-
tion.
2. Slide the main battery bay cover toward the arrow and
remove it.
Opening the main battery bay cover
3. Put the Lithium-Ion battery pack in the bay. Slide the
battery toward the arrow.
Inserting the battery
4. Firmly press the battery until it is secure.