{"product_id":"vivo-y52s-replacement-battery-385v-4900mah-li-polymer","title":"Vivo Y52s Replacement Battery B-O8 3.85V 4900mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVivo Y52s — 3.85V Li-Polymer Replacement Battery (B-O8)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.85V, 4900mAh Li-Polymer cell (18.87Wh) that replaces the original B-O8 battery in the Vivo Y52s smartphone. It fits the Y52s directly, restoring full power capacity to the device. Voltage and physical dimensions match the OEM spec: 91.95 × 62.60 × 4.60mm.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eY52s fitment:\u003c\/strong\u003e\n    The Y52s uses a 3.85V nominal Li-Polymer cell with the B-O8 part number. The connector pinout and BMS handshake on this replacement match the charge IC on the Y52s mainboard, so the fuel gauge IC can read cell state correctly after calibration.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through full charge and discharge on the Y52s platform. The BMS accepted charge protocol without flagging an error state, and the coulomb counter tracked capacity through a complete cycle without dropout.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fuel gauge calibration:\u003c\/strong\u003e\n    On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC recalibrate against the new cell's discharge curve before high-current charging pushes current into an uncalibrated cell.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the Y52s reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThe Y52s fuel gauge IC stores a discharge curve learned from the original cell over months of use. When you install a new cell, that stored curve no longer matches the new cell's actual voltage-to-capacity profile. The phone reads voltage from the cell and maps it against the old curve, so the percentage displayed is off — sometimes by 10–20 points. One full discharge down to auto-shutdown followed by a complete charge to 100% forces the coulomb counter to resync against the new cell.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eSudden shutdown at 20–30% on the replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eThis happens when the fuel gauge IC is still calibrated to the old cell's curve and the reported percentage doesn't reflect actual cell voltage. Under modem transmission load or screen brightness spikes, the cell voltage drops below the BMS cutoff threshold — around 3.0V — before the OS reports 0%. The phone cuts out to protect the cell. Run two full discharge-charge cycles without fast charging; after recalibration, the reported percentage will align with real cell voltage and the shutdowns stop.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391894421594,"sku":"BWCS-BKY520SL-1","price":30.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43391894454362,"sku":"BWCS-BKY520SL-2","price":34.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43391894487130,"sku":"BWCS-BKY520SL-3","price":37.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BKY520SL-1.webp?v=1779142595","url":"https:\/\/batteryweb.com\/products\/vivo-y52s-replacement-battery-385v-4900mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}