Pocket PC Phone User Manual 15When the battery is lowWhen the low-battery warning message appears, immediately save any data you areworking on, perform synchronization with your PC, and turn off your Pocket PC Phone. Theinternal backup battery can only protect the data in case of battery or SIM card change.Data retention in the case of shut down (low battery) is 72 hours.1.4 AccessoriesAC AdapterThe AC adapter allow you to recharge your Pocket PC Phone.USB CableThe optional USB cable allows you to synchronize with a PC .HeadsetThe stereo handset has a volume control and a button where press once to pick up aphone call and hold 2 seconds to end a phone call. During a phone call, press once toswitch between calls.