{"product_id":"compaq-smart-array-5300-controller-replacement-battery-48v-250mah-ni-mh","title":"Compaq Smart Array 5300 Replacement Battery 4.8V 250mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eCompaq Smart Array 5300 Controller — 4.8V Ni-MH Replacement Battery (120978-001)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 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.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eSmart Array 500 \/ 1000 \/ 4200 \/ 5300 compatibility:\u003c\/strong\u003e\n    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.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    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.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003ePost-swap controller mode:\u003c\/strong\u003e\n    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.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eRAID controller staying in write-through mode after battery swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe 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.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eManagement console showing a battery error days after installation\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis 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.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416093753434,"sku":"BWCS-RAC4200SL-1","price":39.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416093786202,"sku":"BWCS-RAC4200SL-2","price":45.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416093818970,"sku":"BWCS-RAC4200SL-3","price":50.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-RAC4200SL-1.webp?v=1779760285","url":"https:\/\/batteryweb.com\/products\/compaq-smart-array-5300-controller-replacement-battery-48v-250mah-ni-mh","provider":"BatteryWeb","version":"1.0","type":"link"}