BBK VIVO Y75 B-D5 Replacement Battery 3.85V 2900mAh

BBK VIVO Y75 Series — 3.85V Li-Polymer Replacement Battery (B-D5)

This is a 3.85V, 2900mAh (11.17Wh) lithium-polymer cell built to the B-D5 specification. It fits the VIVO Y75, VIVO Y75 Dual SIM, VIVO Y75 Dual SIM LTE, and VIVO Y75a. If your original cell has swollen, holds a short charge, or the phone shuts off unexpectedly, this replaces it directly.

• VIVO Y75 variant compatibility: The Y75, Y75 Dual SIM, Y75 Dual SIM LTE, and Y75a all run the same B-D5 form factor — same connector pinout, same BMS handshake protocol, and the same 76.30 × 59.14 × 4.02mm cell envelope. No adapter or modification needed across these variants.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Y75 platform. The BMS handshake completed correctly, charge IC accepted the cell without error flags, and the fuel gauge IC registered state-of-charge without spurious resets.
• First-cycle fast charge protocol: 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 — preventing early percentage drift.

Sudden shutdown at 20–30% on the VIVO Y75 after a cell swap

The VIVO Y75 fuel gauge IC stores a discharge curve from the previous cell. When a new B-D5 cell goes in, the IC may map the old curve onto the new cell's actual voltage profile — causing it to declare "empty" while the cell still has capacity. The phone cuts power when the reported state-of-charge hits zero, even though the terminal voltage hasn't dropped below the BMS floor. One full discharge down to auto-shutdown followed by an uninterrupted charge to 100% forces the coulomb counter to relearn the new cell's curve. After that cycle, the shutdowns stop.

USB-PD or fast charge not working on the first charge after replacement

The charge IC on the Y75 negotiates fast charge protocol during the first handshake with a new cell. A fresh B-D5 cell comes off storage at a lower state-of-charge, and some charge ICs default to standard 5V/1A input until they confirm cell impedance is within expected range. This is not a fault — it resolves after the first full charge cycle completes at standard rate. Plug into the original BBK charger at standard charge, let it reach 100%, then fast charge resumes normally on subsequent cycles.