For the current supply of the terminal Lithium-Ion batteries are used. A rechargeable, not exchangeable by the user, backup battery secures the main memory if the capacity of the main battery is low or during the change of the main battery. The backup battery is charged by the main battery.

Battery	Capacity	Weight	Charging Time	Running Time
HA-D20BAT (3,7V)	1850 mAh	46g	4 hours	10 - 11 hours
HA-D21LBAT (3,7V)	3700 mAh	86g	7 hours	20 - 22 hours
Backup-Battery	10 mAh	-	4 days	10 minutes

For WLAN operation we strongly recommend using the large battery HA-D21LBAT. Further information, especially about calculating the running time can be found in the Hardware Manual.

Maximise Battery Output
 

Note that the battery output depends on the individual use of the terminal. You can extend the output of your battery, if you follow some advice:

• Always charge the terminal, if you sit at the desk, or charge it daily over night.
• If you use the camera, Bluetooth® technology, WLAN or other applications frequently, you should always pay attention to the battery symbol and charge it if necessary.
• Deactivate the camera, Bluetooth® function or WLAN if no Bluetooth® connection is required.
• Like any mobile phone the optional GPRS Backpack will search for a signal, which means outside the supply area the terminal will search continuously for a signal by what the battery will be weakened. If you are in a bad supply area for longer turn the terminal off temporarily.
• Reduce the screen brightness. Adjust the screen so that it will switch off automatically after a short time in which no activity takes place.
• Do not expose the battery to direct sun light or other heat sources. By temperatures over 50 °C the capacity and the running time of a lithium ion battery can be permanently shortened.
• When used at low temperatures, the battery pack has a reduced capacity and will supply power for shorter time. The life span of the battery pack is also shortened.
• For further details refer to the User's Guide that comes with each terminal.

Backup Battery

If both main and backup battery are fully depleted, you might not be able to switch the device on. Insert a charged main battery and wait for the backup battery to recover.