{"product_id":"vivo-x9i-replacement-battery-385v-3150mah-li-polymer","title":"Vivo X9i B-B9 Compatible Battery 3.85V 3150mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVivo X9i — 3.85V Li-Polymer Replacement Battery (B-B9)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3150mAh (12.13Wh) Li-Polymer cell at 3.85V, built to the same dimensions as the original B-B9 unit fitted in the Vivo X9i. It replaces a swollen, degraded, or non-charging original cell in the X9i mid-range Android handset. Capacity figures come from the product data — 3150mAh is what this cell is rated at, not an estimate.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eX9i fitment:\u003c\/strong\u003e\n    The X9i uses a sealed rear panel with a specific cell footprint — 82.90 x 62.40 x 3.40mm. This cell matches those dimensions exactly. The connector orientation and tab length match the original BMS harness routing, so no forced bending at the flex point.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran charge and discharge cycles through the X9i charge IC and confirmed the BMS handshake completes correctly. The protection circuit trips at the expected undervoltage threshold and resets cleanly on reconnection to a charger.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    On first use after installation, disable fast charging for one full discharge-charge cycle. The X9i's fuel gauge IC is calibrated against the old cell's discharge curve. Running one slow cycle against the new cell gives the coulomb counter accurate data before high-current charging is applied.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the X9i after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA new cell has a discharge curve the fuel gauge IC hasn't mapped yet. When the X9i drives the modem or display at high brightness, the instantaneous current draw causes a voltage sag the IC didn't anticipate. The phone reads a safe percentage but the cell voltage collapses below the shutdown threshold under load. One full slow discharge down to 3.0V followed by a full slow charge resets the coulomb counter and eliminates most of these shutdowns.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eVivo's fast charge protocol not activating after battery replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe X9i uses a proprietary charge protocol negotiated between the adapter and the charge IC — not standard USB-PD. On the first cycle with a new cell, the charge IC may default to a conservative 5V\/1A profile while it verifies the new cell's impedance is within range. This is normal behaviour, not a fault. After one complete charge cycle the IC re-negotiates the higher-current profile and fast charging resumes. If it still fails after two cycles, verify the charge port pins are clean and the original fast charge adapter is in use.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43392074088538,"sku":"BWCS-BYX920SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43392074121306,"sku":"BWCS-BYX920SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43392074154074,"sku":"BWCS-BYX920SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BYX920SL-1.webp?v=1779143621","url":"https:\/\/batteryweb.com\/products\/vivo-x9i-replacement-battery-385v-3150mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}