Oppo Reno Z BLP717 Replacement Battery 3.85V 3950mAh

Oppo Reno Z — 3.85V Li-Polymer Replacement Battery (BLP717)

The BLP717 is the OEM-matched cell for the Oppo Reno Z, Reno Z Dual SIM, Reno Z Dual SIM TD-LTE, and PCDM10 variants. It runs at 3.85V with a 3950mAh (15.21Wh) capacity using Li-Polymer chemistry. If your Reno Z shuts down early, charges slowly, or barely lasts a morning, the original cell has degraded and this is the direct swap.

• Reno Z variant coverage: The Reno Z, Reno Z Dual SIM, Reno Z Dual SIM TD-LTE, and PCDM10 all use the same BLP717 footprint, connector pinout, and BMS handshake. No adapter or wiring change needed across these variants — the battery management protocol is identical on the motherboard side.
• Bench tested on actual hardware: We cycled this cell through a full charge and discharge on Reno Z hardware. The BMS accepted the cell without a fault flag, charge current ramped correctly through CC/CV stages, and the fuel gauge IC logged the new capacity without manual intervention.
• First-cycle fast charge protocol: On first use after installation, turn off VOOC fast charging for one complete discharge-charge cycle. The fuel gauge IC needs to map the new cell's discharge curve before high-current fast charging pushes significant amperage into an uncalibrated cell. One standard charge cycle is all it takes.

Why the Reno Z reports the wrong battery percentage after a cell swap

The Reno Z uses a coulomb counter IC that tracks charge in and out of the original cell across its entire service life. When you install a new cell, that counter still holds the old cell's calibration data — it has no record of the new cell's actual capacity curve. This mismatch causes the percentage display to jump, stall, or read high while the real voltage is already dropping. One full discharge down to automatic shutdown, followed by a complete uninterrupted charge to 100%, forces the IC to rebuild its reference table against the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem, display, or a background process pulls a short current spike that the cell cannot sustain at its present state of charge. The BMS reads the resulting voltage dip as a hard undervoltage event and cuts output before the percentage hits zero. It is not a faulty battery — it is the fuel gauge IC using stale data to predict remaining capacity. Run one full discharge-charge cycle without interruption, let the percentage reach 0% naturally and charge back to 100%, and the shutdowns stop once the IC has an accurate voltage-to-capacity map for the new cell.