{"product_id":"bbk-vivo-x5-pro-replacement-battery-38v-2300mah-li-polymer","title":"BBK VIVO X5 Pro B-81 Replacement Battery 3.8V 2300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eBBK VIVO X5 Pro — 3.8V Li-Polymer Replacement Battery (B-81)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThis is a 3.8V, 2300mAh lithium-polymer cell built to fit the VIVO X5 Pro and X5Pro smartphones. It replaces OEM part numbers B-81 and BK-B-81 directly. Total energy capacity is 8.74Wh at the rated voltage.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eVIVO X5 Pro and X5Pro compatibility:\u003c\/strong\u003e\n    Both model designations share the same battery bay dimensions (107.00 × 44.52 × 3.05 mm), the same 3.8V nominal rail, and the same B-81 connector pinout. No adaptation or modification is needed between the two variants.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell on a VIVO X5 Pro unit and confirmed the BMS handshake completed on first boot. Charge acceptance started immediately and the protection circuit tripped correctly at the low-voltage cutoff threshold — no anomalous shutdowns during testing.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFuel gauge recalibration on first use:\u003c\/strong\u003e\n    After installation, disable fast charging and run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the coulomb counter a complete reference curve against the new cell before the phone starts reporting accurate percentages.\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 a replacement cell\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eA new lithium-polymer cell has a slightly different internal resistance profile than the original. When the VIVO X5 Pro's modem fires a high-current burst — during a call, GPS lock, or screen-on wake — voltage sags sharply across that resistance. If the sag pulls the cell below the BMS undervoltage trip point, the phone cuts out even though the fuel gauge still reads 20–30%. The fix is one full calibration cycle: discharge to shutdown, then charge to 100% without interruption. After that cycle, the fuel gauge IC maps its thresholds to the new cell's actual voltage curve and the false cutoffs stop.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003ePhone not powering on after the replacement battery sat in storage\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eLithium-polymer cells self-discharge in storage. If this battery dropped below approximately 2.5V per cell before installation, the BMS will have entered lockout mode to prevent damage — and the phone will show no response at all when you press the power button. Connect the phone to a wall charger, not a PC USB port, and leave it for 15–20 minutes without pressing anything. The charge IC trickle-charges the cell at low current until it climbs back above the BMS re-enable threshold, typically around 2.9–3.0V, at which point normal charging resumes automatically.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43404155617370,"sku":"BWCS-BYX521SL-1","price":23.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 2 Year","offer_id":43404155650138,"sku":"BWCS-BYX521SL-2","price":26.99,"currency_code":"USD","in_stock":true},{"title":"Warranty 3 Year","offer_id":43404155682906,"sku":"BWCS-BYX521SL-3","price":29.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BYX521SL-1.webp?v=1779369080","url":"https:\/\/batteryweb.com\/products\/bbk-vivo-x5-pro-replacement-battery-38v-2300mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}