Sprint MF975s User Manual page 25

3. Plug the AC adapter into an electrical outlet.
 The indicator light illuminates when charging starts. The light goes off when the battery is fully
charged. Fully charging a battery may take up to three hours.
4. After charging, disconnect the device from the charger.

Unplug the AC adapter from the outlet, and remove the micro USB cable from the device and
the AC adapter.
MF975S and AC Adapter Becoming Warm or Hot
Your device and the AC adapter may become warm while charging. This is not a malfunction.
However, stop using them immediately if they become extremely hot; this could indicate a malfunction.
Charge Using a USB to PC Connection
Use the supplied micro USB cable when charging via a computer's USB port.
Before using a PC connection to charge your device, ensure that the computer is turned on. Depending
on the type of connection or port configuration, your device's battery may not charge.
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