Vivo IQOO 11S BA01 Replacement Battery 7.78V 2250mAh

Vivo IQOO 11S / V2304A — 7.78V Li-Polymer Replacement Battery (BA01)

This is a 7.78V, 2250mAh (17.51Wh) Li-Polymer replacement battery for the Vivo IQOO 11S and V2304A smartphones. It matches the OEM part number BA01 and fits the original battery bay without modification. Swap it in when the original cell no longer holds enough charge for a full day of use.

• IQOO 11S and V2304A compatibility: Both model numbers reference the same hardware platform. They share the same battery bay dimensions, BMS connector pinout, and fuel gauge communication protocol — so one cell covers both variants without adapter or modification.
• Bench tested on actual hardware: We cycled this cell on the IQOO 11S platform and confirmed the BMS handshake, charge termination at full voltage, and stable discharge down to cutoff. The protection circuit tripped correctly at low-voltage threshold and recovered on reconnect.
• First-cycle fast charge behaviour: 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 charging pushes significant amperage into an uncalibrated cell.

Sudden shutdown at 20–30% on the replacement cell

The IQOO 11S uses a coulomb counter-based fuel gauge IC that was calibrated to the original cell's internal resistance and discharge curve. A new cell has different impedance characteristics, so the fuel gauge's stored lookup table no longer reflects actual remaining capacity. Under high-load conditions — modem traffic, screen-on, or GPS — voltage sags faster than the IC predicts, and the phone hits hardware undervoltage cutoff before the percentage reaches zero. One full discharge-charge cycle on standard charging recalibrates the counter. After that cycle, the reported percentage should track actual cell state more accurately.

USB-PD or proprietary fast charge not activating on first cycle after swap

Vivo's fast charge protocol requires the BMS to signal readiness to the charge IC before high-current delivery begins. On a fresh cell, the BMS initialises in a conservative state and may not respond to the fast charge handshake on the first cycle. The charge IC falls back to standard 5V input as a result. Complete one full charge at standard speed, then reconnect the original fast charger — the BMS should complete initialisation and accept the full fast charge current. If fast charging still does not activate, confirm the charger output at the cable end is reaching the expected voltage.