{"product_id":"vivo-v2145-replacement-battery-778v-2300mah-li-polymer","title":"Vivo B-U3 V2145 Replacement Battery 7.78V 2300mAh","description":"\u003cdiv class=\"bpw-desc\"\u003e\n  \u003ch2 class=\"bpw-desc-h2\"\u003eVivo X80 Pro 5G \/ V2145 \/ V2185A — 7.78V Li-Polymer Replacement Battery (B-U3)\u003c\/h2\u003e\n\n  \u003cp class=\"bpw-desc-lead\"\u003eThe B-U3 is a 7.78V, 2300mAh lithium-polymer cell that fits the Vivo V2145, V2185A, and X80 Pro 5G. It replaces a degraded or failed original battery and restores power delivery to the processor, display, and cellular radio. Capacity is 17.89Wh — matched to the original cell specification.\u003c\/p\u003e\n\n  \u003cul class=\"bpw-desc-bullets\"\u003e\n    \u003cli\u003e\n\u003cstrong\u003eV2145, V2185A, and X80 Pro 5G compatibility:\u003c\/strong\u003e\n    All three models share the same 7.78V dual-cell Li-Polymer architecture and connector pinout. The BMS handshake protocol and charge termination voltage are identical across this platform, so one cell fits all three without modification.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eBench tested on actual hardware:\u003c\/strong\u003e\n    We cycled this cell through charge and discharge on the X80 Pro 5G platform. The BMS accepted charge termination at 8.72V, held low-voltage cutoff at 6.0V, and showed no thermal events across three full cycles.\u003c\/li\u003e\n\n    \u003cli\u003e\n\u003cstrong\u003eFirst-cycle fast charge behaviour:\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 its coulomb counter against the new cell's discharge curve before high-current fast charging pushes elevated 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\"\u003eSudden shutdown at 20–30% on the X80 Pro 5G after a cell swap\u003c\/h3\u003e\n\n  \u003cp class=\"bpw-desc-p\"\u003eA fresh B-U3 cell has a discharge curve the fuel gauge IC has never seen. The IC still references the old cell's voltage-to-capacity map, so it misreads actual state of charge. Under modem or display load, the cell voltage drops sharply at the real empty point — which the OS thinks is still 20–30%. The phone shuts down to protect the cell from going below its 6.0V cutoff. One full discharge-charge cycle corrects the coulomb counter and eliminates the premature shutdown.\u003c\/p\u003e\n\n  \u003ch3 class=\"bpw-desc-h3\"\u003eUSB-PD fast charge not working after replacement\u003c\/h3\u003e\n  \u003cp class=\"bpw-desc-p\"\u003eVivo's proprietary fast charge protocol requires a BMS authentication handshake before the charge IC allows high-current delivery. On the first cycle after fitting a new B-U3, the BMS may complete this handshake only at standard 5V input while it initialises. Charge the phone once to 100% using the original Vivo charger at standard rate. After that first full cycle, fast charge resumes normally on subsequent charges.\u003c\/p\u003e\n\u003c\/div\u003e","brand":"BatteryWeb","offers":[{"title":"Warranty 1 Year","offer_id":43391773048922,"sku":"BWCS-BYX218SL-1","price":43.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 2 Year","offer_id":43391773081690,"sku":"BWCS-BYX218SL-2","price":51.99,"currency_code":"USD","in_stock":false},{"title":"Warranty 3 Year","offer_id":43391773114458,"sku":"BWCS-BYX218SL-3","price":56.99,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0674\/4775\/0746\/files\/BW-CS-BYX218SL-1.webp?v=1779141870","url":"https:\/\/batteryweb.com\/products\/vivo-v2145-replacement-battery-778v-2300mah-li-polymer","provider":"BatteryWeb","version":"1.0","type":"link"}