Dell PowerEdge 4400 RAID Controller Replacement Battery 6V 1500mAh

Dell PowerEdge 4400 — 6V Ni-MH Replacement Battery (1242R / 7142R)

This is a 6V 1500mAh Ni-MH battery for the Dell PowerEdge 4400 RAID controller cache. It powers the controller's write cache during a power loss event, giving the RAID controller time to flush cached data to disk before it's lost. Voltage is 6V, capacity is 1500mAh (9Wh).

• PowerEdge 4400 RAID controller fit: The 4400's RAID controller uses a dedicated battery-backed cache unit that operates on a 6V Ni-MH cell. This battery matches the voltage rail and physical connector required for that unit. OEM part numbers 1242R and 7142R are cross-referenced interchangeably on this controller generation.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS accepted the cell without fault codes, reached full charge without thermal event, and held voltage within the expected range at rest.
• Learn cycle after installation: After fitting this battery, initiate a learn cycle from the controller management interface. Use StorCLI with /cx bbu show to monitor status. The controller holds in write-through mode until the learn cycle completes and the backup window is recalibrated against the new cell's actual capacity.

RAID controller staying in write-through mode after battery swap

After a battery replacement, the controller has no backup window estimate for the new cell. Until it does, it defaults to write-through mode to protect data — this is expected behaviour, not a fault. The learn cycle re-establishes the backup window by fully charging and discharging the cell under controlled conditions. Once the cycle completes and the controller confirms a sufficient backup window, it automatically switches back to write-back mode.

Management console showing a battery error days after installation

The RAID controller runs its battery self-assessment on a timed schedule, not at boot. If the learn cycle hasn't completed when the scheduled test runs, the controller logs a battery error even though the cell is functioning correctly. The error clears once the learn cycle finishes and the backup window estimate updates. Check cycle status with StorCLI /cx bbu show — the state field should read "Learning" and then "Operational" when done.