Unisys Aquanta ES3020 Compatible Battery 3.7V 1800mAh

Unisys Aquanta ES3020 / ES2600 — 3.7V Li-ion Replacement Battery

This 3.7V 1800mAh (6.66Wh) lithium-ion cell replaces the cache backup battery on the Unisys Aquanta ES3020 and ES2600 RAID controllers. It supplies power to the controller's cache memory during unexpected power loss, allowing pending write operations to flush safely before data is lost. Dimensions are 50.70 × 37.55 × 10.50mm — confirm physical fit before installation.

• ES3020 and ES2600 compatibility: Both controllers share the same cache backup architecture and cell voltage rail at 3.7V. The BMS on each platform expects the same charge profile and cutoff thresholds, which is why a single cell covers both.
• Bench tested on actual hardware: We cycled this cell through charge, discharge, and float stages and confirmed the BMS accepted full charge without triggering an over-voltage fault. Cutoff voltage and capacity registration matched what the controller expects before switching from write-through to write-back mode.
• Learn cycle initiation after swap: After fitting the new cell, trigger the battery learn cycle from the controller management interface. On Broadcom/LSI-based platforms, run StorCLI /cx bbu show to confirm the cycle has started. The controller holds 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 persists because the controller has not yet recalibrated its backup window estimate against the new cell. The learn cycle — not the swap itself — is what triggers write-back mode. Until the cycle runs to completion, the controller treats the backup window as unknown and defaults to the safer write-through path. Initiate the learn cycle manually if the controller does not start it automatically within the first hour of normal operation.

Management console reporting a battery error days after installation

The ES3020 and ES2600 controllers run scheduled battery self-assessments on a timed interval, not at every boot. If the console flags a battery error two or three days post-swap, the assessment likely ran before the learn cycle fully completed and logged the result as a fault. Wait for the learn cycle to finish — typically 24 to 72 hours under normal write load — then check whether the error clears on the next scheduled assessment cycle.