{"product_id":"ibm-serveraid-7k-scsi-u320-raid-controller-replacement-battery-37v-1000mah-li-polymer","title":"IBM ServeRAID 7K SCSI U320 Compatible Battery 3.7V 1000mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eIBM ServeRAID 7K SCSI U320 RAID Controller — 3.7V Li-Polymer Replacement Battery (90P5245)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis 3.7V, 1000mAh Li-Polymer cell replaces the backup battery on the IBM ServeRAID 7K SCSI U320 RAID Controller. It powers the controller's cache memory during a system power loss, holding write-pending data until the server recovers. Also cross-references OEM part numbers 71P8642 and 39R8804.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eServeRAID 7K cache backup circuit:\u003c\/strong\u003e\n    The 7K controller uses a dedicated battery-backed write cache. When this cell degrades below the controller's minimum voltage threshold, the card drops to write-through mode — removing the performance benefit of write-back caching until a healthy cell is installed and recalibrated.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran charge and discharge cycles on this cell and confirmed the BMS accepts a full charge without error. The cell voltage held within spec under sustained low-current draw, consistent with cache backup duty.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eLearn cycle after installation:\u003c\/strong\u003e\n    After fitting this battery, trigger a learn cycle from the controller management interface. On systems using StorCLI, run \u003ccode\u003eStorCLI \/cx bbu show\u003c\/code\u003e to monitor status. The controller stays in write-through mode until the learn cycle completes and the backup window estimate is recalibrated 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  \u003cp class=\"bpw-desc-p\"\u003eFitting a new cell does not automatically restore write-back mode. The ServeRAID 7K controller must complete a learn cycle to measure the new cell's actual backup window before it trusts the battery again. Until that cycle finishes — which can take 24 to 72 hours under normal server load — the controller keeps caching disabled as a precaution. Manually initiate the learn cycle via StorCLI or the controller's management interface; do not wait for it to trigger on its own schedule.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eManagement console showing a battery fault days after the swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe ServeRAID 7K runs its battery self-assessment on a timed interval, not at the moment a new cell is detected. A fault flag showing up two or three days post-swap usually means the scheduled assessment ran before the learn cycle had fully recalibrated the new cell. Check battery status with \u003ccode\u003eStorCLI \/cx bbu show\u003c\/code\u003e — if the learn cycle is still in progress, the fault clears automatically once it completes. If the fault persists after a full cycle, verify the cell voltage is reading above 3.5V at rest.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43416092082266,"sku":"BWCS-IBU320SL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43416092115034,"sku":"BWCS-IBU320SL-2","price":34.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43416092147802,"sku":"BWCS-IBU320SL-3","price":37.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-IBU320SL-1.webp?v=1779760241","url":"https:\/\/batteryweb.com\/products\/ibm-serveraid-7k-scsi-u320-raid-controller-replacement-battery-37v-1000mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}