Technical data

SIMATIC Box PC 620 Expansions
5-11
SIMATIC Box PC 620 Manual
C79000-G7076-C639-02
5.3 Replacing the Backup Battery
Battery Power Supply for Real-Time Clock and Configuration
A backup battery (3.6 V-lithium battery) powers the the real-time clock even after
the SIMATIC Box PC 620 is switched off. In addition to the time of day, all the in-
formation about the SIMATIC Box PC 620 (device configuration) is stored in RAM.
If the backup battery fails or is removed, all these data are lost.
The clock uses very little power and the lithium battery has a high capacity so that
the battery can provide backup power for the real-time clock for many years and
seldom needs to be replaced.
Battery Voltage too Low
If the battery voltage is too low, the time is lost, and a correct configuration of the
device can no longer be guaranteed.
Replacing tthe Battery
In this case, you must replace the backup battery. The battery is on the
motherboard.
To change the battery, proceed as follows:
1. Switch off your SIMATIC Box PC 620 and remove the power cable and all the
connecting cables.
2. Open the unit as described in Section 5.1.
3. Change the backup battery inserted in the motherboard by pulling out the
connector and undoing the cable tie.
4. Secure the new battery in its mounting with a cable tie.
5. Insert the battery connector in the motherboard.
6. Close the unit.