About this replacement
Vivo iQOO 5 Pro — 7.74V Li-Polymer Replacement Battery (B-O2)
This is a 7.74V, 2000mAh Li-Polymer replacement cell for the Vivo iQOO 5 Pro, iQOO 5 Pro 5G, and V2025A. It directly replaces the original B-O2 battery. Swap it in when the original cell can no longer hold charge or shuts the phone down unexpectedly.
- iQOO 5 Pro / V2025A platform fit: The iQOO 5 Pro, iQOO 5 Pro 5G, and V2025A all run the same dual-cell 7.74V configuration with identical connector pin-out and BMS handshake protocol — one cell covers all three variants.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on iQOO 5 Pro hardware. The BMS accepted the cell without fault codes, and the charge IC stepped through the correct CC/CV phases to full termination.
- First-cycle fast charge protocol: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC build an accurate discharge curve for the new cell before high-current fast charging pushes current into an uncalibrated state.
Sudden shutdown at 20–30% on the replacement cell
The iQOO 5 Pro's modem and display pull hard, simultaneous current spikes during 5G handoff and screen wake events. A new cell with a discharge curve the fuel gauge IC hasn't mapped yet will hit a voltage sag the IC misreads as adequate capacity — until the load spike collapses cell voltage below the BMS cutoff threshold. The phone reads 25% and then cuts off instantly. One full discharge-charge cycle at standard rate recalibrates the coulomb counter and eliminates this behaviour.
USB-PD fast charge not accepting the replacement cell on first cycle
After a cell swap, the charge IC briefly rejects high-current fast charge modes until it has confirmed the new cell's impedance profile. Vivo's proprietary fast charge protocol negotiates current levels against BMS data — a fresh cell with no charge history causes the IC to fall back to standard 5V charging on the first cycle. This is normal and not a fault with the replacement cell. Plug in, let it complete one full standard-rate charge, and fast charging will re-enable automatically on the next session.