BBK VIVO Y97 B-E8 Compatible Battery 3.85V 3250mAh

BBK VIVO Y97 / V1813 Series — 3.85V Li-Polymer Replacement Battery (B-E8)

This is a 3.85V, 3250mAh (12.51Wh) Li-Polymer cell that replaces the original B-E8 battery in the VIVO Y97, V1813, V1813T, and V1813A smartphones. It fits the standard battery bay and connects to the same ribbon connector as the factory unit. Swap it in when the original cell no longer holds charge or causes unexpected shutdowns.

• V1813 platform compatibility: The V1813, V1813T, and V1813A variants all run the same power rail at 3.85V nominal and share an identical connector pinout and BMS handshake protocol — one cell covers all three board revisions.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the V1813 board. The BMS accepted the cell on first connection, charge termination triggered correctly at 4.35V, and low-voltage cutoff engaged cleanly without tripping the board's protection circuit.
• Fuel gauge recalibration after install: On first use after fitting this cell, disable fast charging and run one full discharge down to auto-shutoff, then charge to 100% on standard current. This lets the fuel gauge IC map its coulomb counter to the new cell's actual discharge curve before any high-current charging session skews the calibration.

Why the VIVO Y97 reports wrong battery percentage after a cell swap

The Y97 uses a coulomb-counting fuel gauge IC that builds its reference model from the original cell's charge and discharge history. When you install a new cell, the IC still references the old degraded curve, so the percentage display is off — sometimes by 15–20 points. One complete discharge-to-shutoff and charge-to-100% cycle resets the learned curve. After that single cycle, the reported percentage tracks accurately against actual remaining capacity.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under modem or screen load — a voltage cliff the OS doesn't predict fast enough to warn you. The fuel gauge still reads 20–30% capacity remaining, but actual terminal voltage has already fallen below the board's cutoff threshold. It's most common in the first few cycles before the gauge IC recalibrates to the new cell. Run the recalibration cycle described above; if shutdowns persist past cycle three, check that the battery ribbon connector is fully seated — a partial contact adds resistance and deepens the sag.