IBM V9000 Control Cabinet Alarm Light Flashing: CMOS Battery Threshold Microcode Issue

IBM L3 has analyzed the issue

The alarm light is due to the CMOS battery voltage exceeding the alarm threshold. (The CMOS battery voltage threshold set by firmware is too strict.)

But CMOS battery can still be used. If we don't replace it, it won't affect the storage operation.

According to IBM L3's analysis of this issue, the alarm light is triggered because the CMOS battery voltage exceeds the alarm threshold. The CMOS battery remains usable, and not replacing it will not affect storage operation.

This is due to the firmware having a voltage threshold for CMOS battery detection that is set too low.

Regarding this firmware bug, the error reported in this instance differs from the previous one: previously, a 'low battery' warning was issued, whereas now a 'high voltage' warning is generated, causing an alarm. This issue is resolved by upgrading to firmware version 8.2.1.4 or later; version 8.2.1.18 is the latest release in the 8.2 series.

In my opinion, the older BMC firmware likely had a low threshold setting for the CMOS battery. After the upgrade, the threshold increases, allowing for higher CMOS battery voltages without triggering an error. Since the yellow light does not impact system functionality and the firmware upgrade process is significant, it may be considered optional to skip the upgrade.