Mylex DAC960PG, Installation Manual

Page: 82 / 106

Functional Description
B-4 DAC960PG Installation Guide
The battery power meter indicates the battery capacity in hours. It will
indicate a charge duration of up to 100 hours. The firmware will detect the
Mylex supplied SIMM and assign a value based upon the charge level of the
battery and the power consumption rate of the SIMM.
m
Caution
Do not use SIMMs which are not supplied by Mylex
without first contacting Mylex Technical Support.
The charge level meter displays the charge state of the battery expressed in
percent. A fully charged battery will cause the charge level meter to indicate
100%.
When the meter on the right indicates the battery is fully charged, the meter
on the left will indicate the maximum time in hours that the battery can be
expected to maintain cache data integrity. This value will vary depending
upon which Mylex supplied SIMM is being used (see Tabe 4-1).
☛
Note
When the charge level is 100%, the current number of
hours and maximum number of hours (printed out
below the left dial) will be equal.
Battery and Charge Circuit
On-board Battery
The on-board battery is rated at 3.6 v with a capacity of 650 mAH. The
IBBU has a DC-DC converter that converts the 3.6 v from the battery to 5 v,
which is the nominal voltage needed to replace V
CC
if a power failure should
occur.
Battery Charger
Battery charging and conditioning are automatically handled by the IBBU.
No manual preconditioning needs to be performed by the user.
The battery charger uses the input of the +12 vdc from the PCI bus to charge
the battery. Internal current-limiting circuitry along with the IBBU’s gas
gauge circuitry are used to control the battery’s rate of charge for maximum
efficiency. If the battery capacity falls below a predetermined level (which
is likely to happen during a power failure), the battery charger goes into a
quick charge mode. If the battery is fully charged, the charger goes into a
trickle charge mode.