BLP973 Oppo Reno9 5G Compatible Battery 3.87V 4300mAh

Oppo Reno9 5G / Reno 9 Pro — 3.87V Li-Polymer Replacement Battery (BLP973)

The BLP973 is a 3.87V, 4300mAh (16.64Wh) Li-Polymer cell for the Oppo Reno9 5G (PHM110) and Reno 9 Pro (PGX110). It replaces the original cell when capacity has degraded from normal charge-cycle aging. Swapping this cell restores the phone's ability to hold a full charge without the symptoms that come with a worn cell.

• Reno9 5G and Reno 9 Pro compatibility: Both the PHM110 and PGX110 share the same battery bay dimensions, connector pinout, and BMS handshake protocol — one cell covers both variants without modification.
• Bench tested on actual hardware: We ran the BLP973 through charge and discharge cycles on the Reno9 5G platform. The BMS accepted the cell, protection cutoffs triggered correctly at the low-voltage threshold, and the charge IC completed a full charge cycle without fault flags.
• Fuel gauge recalibration on first use: After installation, disable SUPERVOOC fast charging and run one complete discharge-to-charge cycle at standard 10W. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes amperage into an uncalibrated coulomb counter.

Why the Reno9 5G shuts down suddenly at 20–30% after a battery swap

A sudden shutdown in the 20–30% range is not a faulty cell — it is a voltage cliff event. The fuel gauge IC still holds calibration data from the old, degraded cell and does not know where the new cell's actual low-voltage knee sits. Under load from the 5G modem or the AMOLED panel, the cell voltage drops faster than the gauge predicts, and the BMS cuts power before the percentage reads zero. One full discharge-to-charge cycle at standard rate resets the coulomb counter and eliminates most cliff shutdowns.

SUPERVOOC fast charge not activating on the replacement cell

SUPERVOOC negotiation requires the charge IC to confirm cell impedance is within an expected range before the protocol steps up to high current. A brand-new cell has slightly higher internal impedance than a broken-in cell, so the IC stays at standard rate on the first cycle. This is not a compatibility failure — it is a built-in protection behaviour. Complete one full charge cycle at the standard rate first; impedance drops as the cell conditions, and SUPERVOOC will activate normally on the second cycle.