Siemens alarm 1: Battery alarm power supply
SINUMERIK 810/820 legacy alarm · Siemens 810/820
What it means
The back-up battery voltage in the central control unit (CCU) dropped below the warning threshold, so buffered NC/PLC user memory is no longer reliably retained. The manual warns not to switch the control off until parameters are secured and the battery replaced, otherwise a full reload and recommissioning follows.
Likely causes
- Back-up battery exhausted (multi-year service life typical)
- Corroded contacts in the battery holder
- Long periods powered down without battery refresh
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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backup cells per CCU battery holder (3.6 V lithium cells typical)
battery · Common cause
Need the part urgently?
Send us alarm 1 with your machine details — typical RFQ turnaround is 24–48h.