Compaq Smart Array 5300 Replacement Battery 4.8V 250mAh
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Compaq Smart Array 5300 Replacement Battery 4.8V 250mAh - is backordered and will ship as soon as it is back in stock.
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Battery Care Tips
Battery Care Tips
🔹 Getting Started
Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.
🔹 Keep It Healthy
Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.
Delivery and Shipping
Delivery and Shipping
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Disclaimer
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🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.
Compaq Smart Array 5300 Replacement Battery 4.8V 250mAh - is backordered and will ship as soon as it is back in stock.
Voltage
4.8V
Amp
250mAh
Compaq Smart Array 5300 Controller — 4.8V Ni-MH Replacement Battery (120978-001)
This is a 4.8V, 250mAh Ni-MH cache backup battery for the Compaq Smart Array 5300 RAID controller. It holds controller cache memory during a power failure, protecting pending write operations from being lost. It also fits the Smart Array 500, Smart Array 1000, and Smart Array 4200 controllers sharing the same voltage rail and connector spec.
- Smart Array 500 / 1000 / 4200 / 5300 compatibility: These controllers share a 4.8V Ni-MH cell format with the same connector pinout and BMS handshake protocol. Swapping between supported models does not require a firmware change — the controller reads cell chemistry and voltage directly.
- Bench tested on actual hardware: We ran this cell on a Smart Array 5300 under simulated cache load. The BMS accepted the cell without fault codes, and the controller transitioned from write-through to write-back mode after the learn cycle completed.
- Post-swap controller mode: After installing this battery, the Smart Array controller holds in write-through mode until its learn cycle finishes — this is normal. Do not force a reboot to clear the status. Let the cycle run to completion so the controller can recalibrate its backup window estimate against the new cell's actual capacity.
RAID controller staying in write-through mode after battery swap
The Smart Array controller does not automatically switch to write-back mode on first boot after a battery replacement. It requires a completed learn cycle to recalibrate the backup window against the new cell. Until that cycle finishes, the controller treats the battery as unqualified and keeps write-through mode active as a data-safety measure. On HP Array Configuration Utility or ACU, check the battery status tab — the learn cycle typically completes within 24 to 72 hours under normal server load.
Management console showing a battery error days after installation
This catches many admins off guard — the controller's battery assessment does not run at boot, it runs on a timed interval set in firmware. A battery replaced on day one may not be assessed until the next scheduled test window, which can be 48 to 96 hours later. If the error appeared days after the swap, check whether the learn cycle had actually completed before the assessment ran. Confirm cell voltage is at or above 4.6V at rest using the Array Configuration Utility before assuming the cell is faulty.
Compatible Models
Replaces Part Numbers
Technical Specifications
Product Highlights
- Brand: Compaq
- Manufacturer: CS
- Series: Standard
- Color: Black
- Product Type: Ni-MH
- Battery Type: Ni-MH
- Warranty: 12 Months
- Bulk Orders: sales@batteryweb.com
Frequently Asked Questions
The Smart Array 5300 went back to write-through mode overnight — did the new battery fail?
Not necessarily. The controller returns to write-through mode whenever it cannot confirm a valid backup window, which happens after any battery swap until the learn cycle recalibrates the new cell. The learn cycle runs under normal operational load and takes 24 to 72 hours to complete. Do not interrupt it with a reboot. Check the battery status in HP Array Configuration Utility — once the cycle completes and the backup window is confirmed, the controller switches back to write-back mode automatically.
The battery self-test is failing on the Smart Array controller three days after I installed the new cell — what's wrong?
A self-test failure this soon after installation almost always means the learn cycle has not finished, not that the cell is defective. The controller's self-test measures the backup window against a recalibrated threshold — if the cycle is still in progress, that threshold has no valid baseline yet and the test fails by default. Let the learn cycle run to full completion without rebooting the server. If the self-test still fails after 72 hours, check resting cell voltage — it should read at or above 4.6V.
The backup window on the new Smart Array battery is shorter than what the old one showed — is the capacity wrong?
The backup window estimate recalibrates over two to three full learn cycles, not just one. A fresh Ni-MH cell behaves slightly differently from a conditioned cell, and the controller's first backup window estimate after a swap is conservative by design. Run two full learn cycles under normal server load and check the window again. If it remains significantly shorter than expected after three cycles, verify the cell voltage at end-of-charge reaches 4.8V using the Array Configuration Utility battery status screen.
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