HEIDENHAIN MANUALplus 620 Technical Manual page 241

3.19 Buffer Battery
January 2012
Note
Make a data backup before changing the buffer battery.
Danger
When exchanging the buffer battery, remember:
Switch off the machine and the control.
The buffer battery may be exchanged only by trained personnel.
Battery type: 1 Lithium battery, type CR 2450N (Renata), ID 315 878-01
If the voltage of the buffer battery falls below 2.6 V, the error message
Exchange buffer battery appears. If the voltage does not rise above 2.6 V
again, the error message is reactivated after 30 minutes. You can determine
the voltage of the buffer battery with the OLM, see "Diagnosis with the Online
Monitor (OLM)" on page 1162.
To exchange the battery:
 The buffer battery is on the main board of the MC.
 Loosen the screws securing the rear housing cover of the MC.
 Remove the cover.

The buffer battery is at the border of the PCB:

Exchange the buffer battery; the new battery can be inserted in only one
position.
3.19 Buffer Battery
Buffer battery
241