About this replacement
Vivo iQOO Neo5 5G — 7.74V Li-Polymer Replacement Battery (B-P5)
The B-P5 is a 7.74V lithium-polymer cell rated at 2100mAh (16.25Wh), built to restore power to the Vivo iQOO Neo5 5G and iQOO 7 5G. It also fits the I1012 and V2055A variants. Swap it in when the original cell no longer holds enough charge to carry the phone through a normal day.
- Neo5 5G and iQOO 7 5G platform fit: Both handsets share the same dual-cell Li-Polymer pack architecture, connector pinout, and BMS handshake — so the same B-P5 cell services the full lineup without modification.
- Bench tested on actual hardware: We ran this cell through charge, discharge, and load cycles on the iQOO Neo5 5G platform. The BMS accepted the cell on first insertion, voltage read correctly at the fuel gauge IC, and charge current stepped up through each stage without fault flags.
- First-cycle fast-charge hold: On first use after installation, disable Vivo FlashCharge for one complete discharge-charge cycle. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes into an uncalibrated state.
Sudden shutdown at 20–30% on the replacement cell
New Li-Polymer cells have a steeper voltage cliff than a partially degraded original. When the modem fires at full 5G power or the screen peaks in brightness, current draw spikes hard. If the fuel gauge IC is still calibrated to the old cell's curve, it reads 25% when the actual cell voltage has already dropped below the BMS cutoff threshold — around 3.0V per cell. The BMS trips and the phone shuts off instantly. One full discharge-to-shutdown followed by a complete charge cycle resets the coulomb counter and clears this behaviour.
OS reporting wrong percentage after cell swap
The fuel gauge IC in the iQOO Neo5 5G tracks charge state using a coulomb counter calibrated against the original cell's chemistry profile. Drop in a new cell and that calibration is mismatched — the counter shows 80% when the cell is at 65%, or it jumps erratically between readings. This is not a fault in the replacement cell. Drain the phone until it shuts down automatically, then charge uninterrupted to 100% without removing the cable. After one full cycle the IC recalibrates and percentage readings stabilise.