DS8000 Service Documentation Version 7.5

MAP2190 Rack battery backup set charge low

The batteries in each rack are connected as N+1 (redundant). As soon as line cord AC is connected to the PPSs in a rack, both PPSs in that rack begin charging the batteries. When a battery low condition is reported, the maximum recharge time for the battery backup system has been exceeded so multiple independent failures are indicated.

About this task

A battery low condition can occur while the storage facility is operational or during the storage facility (SFI) IML.

When the battery low condition occurs while the SFI is operational, microcode will log the failure and immediately initiate a forced power off.
When the battery low is detected during the first SFI IML, microcode will pause the IML until the condition is resolved or will time out, log the condition, and boot to AIX.
For either case, the SFI will not be operational and the normal methods of repair will not be possible.

MAP2190 Section-1

Procedure

Determine which rack is failing. From the serviceable event, determine the last character of the SRC field. The last character is the failing rack, starting with "1" for the first rack.
At the failing rack, observe the status display on the front of both PPSs. Are any codes displayed?
- Yes, go to step 3.
- No, go to step 4.
See MAP2340 Codes on the PPS status display. Is the format of the codes Ux (where x is any character)?
- Yes, a battery backup unit is failing. Replace the three battery backup-up service modules in the battery backup service module enclosure referenced in the status code definition.
- No, go to the next step.
The battery backup service modules are charged by both PPSs, through separate PPS to battery cables.
- The only single point of failure for low battery status are the battery service modules or the battery backup service module enclosure.
- It is possible for more than one failure to combine together and cause the low battery charge condition.
Display and repair any related serviceable events for the PPS ad backup battery system. If there are none, contact your next level of support before you replace the following possible failing FRU:
- PPS-1
- PPS-2
- PPS-1 (connector J7) to backup battery enclosure (connector J3) cable
- PPS-2 (connector J7) to backup battery enclosure (connector J4) cable