{"product_id":"bbk-vivo-y17-replacement-battery-38v-2100mah-li-polymer","title":"BK-B-66 BBK VIVO Y17 Compatible Battery 3.8V 2100mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBBK VIVO Y17 Series — 3.8V Li-Polymer Replacement Battery (BK-B-66)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 2100mAh Li-Polymer cell carrying OEM part number BK-B-66. It fits the VIVO Y17, VIVO Y17t, and VIVO Y17W handsets. Capacity and voltage match the original BBK specification exactly — no adapters or modifications needed.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eY17 \/ Y17t \/ Y17W platform fit:\u003c\/strong\u003e\n    All three variants share the same battery bay dimensions, connector pinout, and BMS communication protocol. The Y17W differs only in regional firmware — the battery hardware is identical across all three, so one cell covers the full range.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We ran this cell through a full charge and discharge cycle on a Y17 unit. The BMS handshake completed on first connection, charge IC accepted the cell without error flags, and the fuel gauge IC began tracking state-of-charge correctly within the first cycle.\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 and run one complete discharge-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes amperage into an uncalibrated cell — preventing early percentage jumps.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003chr class=\"bpw-desc-divider\"\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eWhy the VIVO Y17 reports wrong battery percentage after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eThe Y17 uses a coulomb-counter-based fuel gauge IC that builds its state-of-charge model from the original cell's discharge curve. When a new cell goes in, that stored curve no longer matches the physical cell — so the IC reports stale or inaccurate percentages. The result is jumpy readings or a percentage that doesn't match actual remaining charge. One full slow discharge down to automatic shutdown, followed by a full charge to 100%, resets the calibration baseline. After that cycle the gauge tracks accurately 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 modem or display pulls a high current burst and the cell voltage drops below the BMS low-voltage cutoff — even though the gauge still reads 20–30%. It's a calibration gap, not a faulty cell. The fuel gauge IC inherited calibration data from the degraded original cell, so it overestimates remaining capacity at lower charge levels. Run one full discharge-charge cycle at standard (non-fast) charging speed. After recalibration, the cutoff threshold aligns with the new cell's actual voltage floor near 3.4V.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404233015386,"sku":"BWCS-BKY170SL-1","price":24.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404233048154,"sku":"BWCS-BKY170SL-2","price":27.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404233080922,"sku":"BWCS-BKY170SL-3","price":30.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BKY170SL-1.webp?v=1779369447","url":"https:\/\/batteryweb.com\/products\/bbk-vivo-y17-replacement-battery-38v-2100mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}