You must determine if the battery is faulty before you replace it.
See Accessing the SP.
-> show /System/Open_Problems Open Problems (1) Date/Time Subsystems Component ------------------------ ------------------ ------------ Thu Dec 17 05:00:01 2015 System MB (Motherboard) fault.chassis.battery.fail (Probability:100, UUID:76a2179a-51bd-c836-a7f1-af62953577fa, Resource:/SYS/MB, Part Number:7092577, Serial Number:AK00329231, Reference Document:http://support.oracle.com/msg/---) ->
Start at Remove the Air Duct Assembly.
See Open Problem Faults and Oracle ILOM Legacy Target Replaceable Components.
-> show /SYS/MB/V_VBAT alarm_status /SYS/MB/V_VBAT Properties: alarm_status = state_asserted ->
If the alarm status is anything other than cleared, replace the battery. Start at Remove the Air Duct Assembly.