Vivo BA61 V2419 Replacement Battery 3.89V 5350mAh

Vivo V2419 / Y19s — 3.89V Li-Polymer Replacement Battery (BA61)

This is a 3.89V, 5350mAh (20.81Wh) Li-Polymer cell built to replace the original BA61 battery in the Vivo V2419 and Y19s smartphones. It restores power to the display, processor, and connectivity hardware when the original cell has degraded or failed to hold charge. Voltage and connector match the OEM spec exactly.

• V2419 and Y19s platform fit: Both models share the same battery bay dimensions, connector pinout, and BMS handshake protocol, which is why a single BA61 cell covers both. The fuel gauge IC on each device reads the same charge curve, so calibration behaviour is consistent across the two.
• Bench tested on actual hardware: We cycled this cell through a full discharge and charge sequence on the V2419. The BMS accepted the handshake without error flags, and the charge IC stepped correctly through trickle, constant-current, and constant-voltage phases.
• Fuel gauge recalibration on first use: 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 and false low-battery shutdowns.

Sudden shutdown at 20–30% on the Vivo V2419 after a cell swap

New Li-Polymer cells have a steeper voltage cliff than worn cells the fuel gauge IC was originally calibrated to. When modem activity or screen brightness spikes current draw, the cell voltage drops sharply — the BMS triggers a cutoff even though the reported percentage still reads 20–30%. This is not a faulty cell. One full discharge down to auto-shutdown, followed by a full uninterrupted charge, resets the coulomb counter and flattens the reported curve against the actual cell behaviour. After one complete cycle, the shutdown threshold tracks correctly at or below 5%.

USB fast charge not activating on the first cycle after replacement

Vivo's proprietary fast charge protocol requires the BMS to confirm cell state before the charge IC allows elevated current. On a fresh replacement cell, the BMS has no stored state data, so the charge IC defaults to standard 5V input on the first cycle as a precaution. This is normal behaviour, not a defect in the battery or the charger. Complete one full standard charge from near-zero to 100%, then reconnect the original fast charger — the BMS will have written enough cell data for the protocol handshake to succeed and fast charge will activate at the correct voltage step.