Nokia 3585 Online User's Manual page 26

Your PCS Phone comes with a rechargeable battery. You should charge
the battery as soon as possible so you can begin using your phone.
Use only a Sprint/Nokia approved desktop charger, travel charger, or
vehicle power adapter to charge your battery.
Keeping track of your battery's charge is important.
If your battery level becomes too low, your phone
automatically turns Off and you'll lose everything
you were just working on and/or be disconnected
from an active call. For a quick check of your
battery's strength level, glance at the battery strength
indicator located in the upper-right corner of your
phone's display screen.
To use the charger:
Plug the cord of the AC adapter into the electrical wall outlet, then
plug the round end into the desk stand charger (or directly into your
phone's AC adapter plug).
Place the phone in the desk stand charger. The screen briefly displays
a "Charging" notification (if the phone is On), followed
immediately by a continuous scrolling battery indicator. If the phone
is Off, only the scrolling indicator is displayed.
When the battery is fully charged, the screen displays a "Battery full"
notification, and the indicator stops scrolling. Unplug the phone
from the charger.
You can recharge the Li-Ion battery before it becomes completely run
down. A completely empty battery takes approximately 4 hours to fully
recharge.