BBK VIVO Y69 Compatible Battery B-C8 3.85V 2900mAh

BBK Vivo Y69 — 3.85V Li-Polymer Replacement Battery (B-C8)

This is a 3.85V, 2900mAh Li-Polymer cell (11.17Wh) for the Vivo Y69, Vivo Y69 Dual SIM, Vivo Y69 Dual SIM TD-LTE, and model 1714. It replaces OEM part B-C8 when the original cell no longer holds charge through a normal day. Physical dimensions are 89.22 × 64.98 × 3.24mm — measure your existing cell before installing.

• Vivo Y69 and 1714 platform fit: These model numbers share the same battery bay dimensions, connector pinout, and BMS communication protocol. The same B-C8 part number covers all variants listed — there is no electrical difference between the standard and Dual SIM TD-LTE builds at the battery level.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on a Vivo Y69 unit. The BMS handshake completed on first insertion, charge IC accepted the cell without flagging an unknown battery warning, and voltage held stable under screen-on and modem-active load.
• First-cycle fuel gauge calibration: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. The fuel gauge IC on the Vivo Y69 is calibrated to the old cell's discharge curve — one full cycle with standard charge current lets it recalibrate against the new cell before fast charging pushes high current into an uncalibrated state.

Sudden shutdown at 20–30% on the Vivo Y69 after a cell swap

This happens because the fuel gauge IC still references the discharge curve of the old, degraded cell. When the new cell reaches the voltage range that previously corresponded to near-empty on the worn cell, the OS interprets it as critically low and forces a shutdown. The phone shuts off even though the new cell has usable charge remaining. One full discharge-charge cycle with the screen on — letting the coulomb counter track the full swing — corrects the mismatch.

Phone warm near the battery during the first few charges after replacement

A new Li-Polymer cell has higher internal impedance than a broken-in cell. The charge IC on the Vivo Y69 pushes current into that higher resistance, which generates more heat than you'd see on a used cell. This is normal for the first three to five charge cycles and reduces as impedance drops with use. If the phone stays warm after five cycles, check that the battery connector is fully seated — a partially connected cell forces the charge IC to work harder.