NonStop S-Series Planning and Configuration Guide (G06.29+)

Planning for System Availability and Support
HP NonStop S-Series Planning and Configuration Guide—523303-021
10-8
Battery Considerations
•
In case of an AC power failure, all equipment in all the system enclosures
continues to operate for the shorter of these two times:
°
The configured maximum power-fail delay time
°
The shortest calculated maximum power-fail delay time of any group in the
entire system
The operating system continues to process data until that shortest calculated
maximum power-fail delay time expires.
The minimum power-fail delay time is in the range 300 through 600 milliseconds.
•
The batteries provide power only for the components in a system enclosure. They
do not provide power for other external system equipment, such as SWAN
concentrators, tape drives, or LAN routers.
Therefore, you need to determine the system impact if processors continue
operating but one or more external devices fail. If external devices used by the
system are not powered by uninterruptible power sources (UPSs) during AC power
failures, unexpected errors might occur.
You might want to configure a shorter maximum power-fail delay time if the loss of
power to external system equipment negates the advantage of having the system
enclosures continue to operate during a power failure. Also, by configuring a
shorter maximum power-fail delay time, the batteries might have enough power to
power the memory for longer than 45 minutes.
•
The batteries are automatically charged while the system is running.
Spare batteries require recharging at least every six months. To recharge your
spare batteries, you can swap them with the batteries currently installed in your
system every three or four months.
•
Batteries are designed to handle occasional power failures that occur at most
computer sites. Frequent power failures (averaging more than once a week) can
cause the batteries to wear out more quickly.
•
For IOAM enclosures, a UPS is optional but recommended where a site UPS is not
available. You can choose to use any UPS that meets the IOAM enclosure power
requirements for all enclosures being powered on from the UPS. One UPS option
to support the IOAM enclosure is the HP R5500 UPS. For additional information,
contact your HP trained service provider.