NetApp 271-00024 RAID Controller Replacement Battery 7.2V 3400mAh

NetApp 271-00024 — 7.2V Li-ion Replacement Battery (271-00024)

This 7.2V, 3400mAh Li-ion cell replaces the backup power unit in NetApp RAID controller cache protection modules. It holds controller cache during unexpected power loss, allowing a clean flush to non-volatile storage before the system goes dark. Part numbers 271-00024, 271-00024+C0, and ES3242 all cross to this cell.

• Cache backup module compatibility: NetApp's RAID controller backup power units share a fixed 7.2V rail and a standardised BMS handshake across the 271-00024 platform. The controller verifies cell voltage on every boot cycle before enabling write-back cache — voltage outside the accepted window keeps the controller in write-through mode regardless of cell condition.
• Bench tested on actual hardware: We ran this cell through a full charge and controlled discharge on a RAID controller backup module. The BMS accepted the cell, reported healthy status, and completed the learn cycle without flagging a fault. Capacity read back within 3% of the 3400mAh rating at the end of the calibration discharge.
• Learn cycle initiation after swap: After installing this cell, trigger the battery learn cycle from your management interface — in ONTAP use system controller battery show, or via StorCLI run /cx bbu show. The controller stays in write-through mode until the learn cycle finishes and posts a verified backup window estimate against this new cell's actual capacity.

RAID controller staying in write-through mode after battery swap

A freshly installed cell does not automatically unlock write-back cache. The controller holds write-through mode until it has completed a full learn cycle and confirmed the backup window meets its minimum threshold. On NetApp systems, this calibration typically takes 24 to 72 hours under normal I/O load. Until the learn cycle posts a passing result, the controller treats the new cell as unverified and keeps write-back disabled as a data protection measure.

ONTAP reporting a battery error days after installation

NetApp's battery assessment does not run at the moment of installation — it runs on a scheduled interval tied to the controller's internal clock. If the first scheduled assessment fires before the learn cycle has completed, ONTAP will log a battery error even on a healthy cell. Let the learn cycle finish fully before treating a console error as a genuine fault. Once the cycle completes and backup window data is posted, re-check with system controller battery show — a passing result clears the error.