IBM 6000 VA LCD 4U, Installation And Maintenance Manual

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Advanced battery management
The UPS comes with the Advanced Battery Management (ABM) function. ABM is a
set of charger controls and automated battery tests. The cyclic charging schemes
enable periods of time when the battery is being fully charged and periods of time
when the charger is disabled. The ABM function operates constantly and cannot be
turned off.
The life of the battery depends on the ambient temperature, the number of duty
cycles, and the prevention of internal corrosion of a battery. Internal battery
corrosion is caused by current flowing through the battery. Internal corrosion can be
reduced if the battery is charged and discharged as little as possible. When the
battery is charged only when necessary, it is called intermittent charging. After the
battery is fully charged, it has the following charge cycles:
2 days charging
28 days resting
2 days charging
28 days resting
Intermittent charging means that corrosion is occurring only during the 2-day
charging cycle. This means that 90% of the time there is no additional corrosion.
During this 30-day cycle, the battery voltage drops by less than 2%, which has no
effect on the backup time of the UPS. During the resting time, the ABM function
constantly monitors the battery status. If the voltage drops below a predetermined
alarm level, the charging cycle is started again. The same happens if the UPS is
needed during the rest period to backup a power failure. This increases the battery
life by an average of 50%.
If the voltage per cell reaches 2.1 volts on the batteries within the first 10 days of
the rest period, a battery failure alarm occurs.
If the voltage per cell reaches 2.1 volts after the first 10 days of rest, the batteries
are charged again for two days. In this case, the rest cycle might be shorter than 28
days as the batteries age.
The ABM function has no impact on the daily operation of the UPS.
For more information about the ABM function, see Retain tip: H205146 at
http://www.ibm.com/support/entry/portal/docdisplay?lndocid=migr-5089474.
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6000 VA UPS and 6000 VA EBM: Installation and Maintenance Guide