Kyocera 2100 Series - Manual (Page 40)

20 Battery
2 BATTERY
Your phone comes with an internal/removable lithium ion (LiIon) battery. To
learn how to install the battery, see page 1.
The battery is partially charged when you receive the phone. Before using
your phone, fully charge the battery.
To charge the battery
Connect the AC Adapter to the proper jack on the bottom of the phone as
shown below, then connect the adapter’s plug to a wall outlet.
Note— You must have at least a partial
charge in the battery to make or receive
calls, regardless of whether or not the AC
Adapter is connected to the phone. The
battery icon is animated as the battery is
charging. The battery is fully charged when
the battery icon looks like . You can
safely recharge the battery at any time, even
if it has a partial charge.