IBM 0X9B0D RAID Controller Replacement Battery 7.4V 5200mAh

IBM 0X9B0D / 0XC9F3 / 271-00011 — 7.4V Li-ion RAID Controller Replacement Battery

This 7.4V, 5200mAh (38.48Wh) lithium-ion cell replaces the backup battery on IBM RAID controllers including the 0X9B0D, 0XC9F3, 271-00011, and AVT-900486 platforms. It maintains power to cache memory during unexpected shutdowns, giving the controller time to flush pending writes to disk. Without a functioning battery, the controller falls back to write-through mode and cache-backed performance disappears.

• Multi-model fit across IBM cache battery platforms: These controllers share the same 7.4V two-cell Li-ion architecture and connector footprint. The BMS on each platform validates cell voltage at boot — stay within the 6.0V–8.4V operating window and the controller accepts the new cell without manual override.
• Bench tested on actual hardware: We ran this cell through charge, float, and simulated load discharge cycles. The BMS reported full recognition on first connection; charge acceptance was clean from the first cycle with no balancing faults flagged.
• Learn cycle initiation after swap: After installation, trigger the battery learn cycle from the controller management interface — on ONTAP use system controller battery show; on Broadcom/LSI use StorCLI /cx bbu show. The controller stays in write-through mode until the learn cycle completes and recalibrates the backup window against the new cell's actual capacity.

RAID controller staying in write-through mode after battery swap

Write-through mode after a battery swap is almost always a learn cycle that has not completed — not a faulty cell. The controller does not automatically trust a new battery at full capacity; it schedules a discharge-and-recharge assessment to measure actual backup window duration. On Broadcom/LSI controllers this cycle runs in the background and can take 24–72 hours under normal server load. Until it completes, the controller reports an unknown or insufficient backup window and holds write-through as a safety measure. Confirm progress with StorCLI /cx bbu show — look for "Learn Cycle Active: Yes" and a rising "Relative State of Charge" percentage.

Management console showing a battery fault days after installation

IBM RAID controller firmware runs its battery self-assessment on a timed interval — not at the moment you install the new cell. If the scheduled assessment window falls 48–96 hours after swap, the console can flag a fault that was already present on the old battery and has not yet been cleared by a completed test cycle. Check the timestamp on the fault event; if it predates the first completed learn cycle, the alert is stale. Force a reassessment in ONTAP with system controller battery modify -battery-id <id> -initiate-learn-cycle true and wait for the cycle to post a new backup window value above 0 seconds.