BLP835 Oppo A94 Replacement Battery 3.87V 4300mAh

Oppo A94 / CPH2203 / CPH2205 — 3.87V Li-Polymer Replacement Battery (BLP835)

This is a 3.87V, 4300mAh (16.64Wh) Li-Polymer battery for the Oppo A94 smartphone. It fits models CPH2203, CPH2205, and the A94 2021 variant. Replace it when the original cell no longer holds a useful charge or causes unexpected shutdowns.

• CPH2203 and CPH2205 compatibility: Both variants share the same BLP835 footprint, connector pinout, and BMS handshake protocol. The voltage rail and physical dimensions — 85.30 × 62.66 × 4.80mm — are identical across the A94 lineup, so one cell covers the full model range.
• Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on an A94 unit. The BMS accepted the cell without error, charge current ramped correctly through CC and CV phases, and the charge IC reported full capacity at termination.
• First-cycle fuel gauge recalibration: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle at standard current. The fuel gauge IC is still calibrated to the old cell's discharge curve. One slow cycle lets the coulomb counter establish a clean baseline before high-current charging begins.

Sudden shutdown at 20–30% on the BLP835 replacement cell

This is a voltage cliff issue, not a capacity problem. Under peak load — active screen at full brightness, 4G modem transmitting, or GPS active — the cell voltage drops sharply. If it falls below the BMS protection threshold before the OS reads 0%, the phone cuts out immediately. The fuel gauge IC is reporting state-of-charge from an old discharge curve, so the displayed percentage is ahead of reality. One full slow discharge-charge cycle recalibrates the coulomb counter and the shutdowns stop.

USB-PD or VOOC fast charge not activating on first cycle after replacement

On the first charge after a cell swap, the charge IC may default to standard 5V/1A input instead of negotiating the VOOC or USB-PD fast charge protocol. This happens because the BMS flags the new cell as uncalibrated and limits negotiation until it completes one baseline cycle. Charge the phone fully at standard speed using the original Oppo charger. After that first complete cycle, fast charge protocol negotiation resumes normally and the charging speed returns to rated current.