Oppo Reno 4 5G BLP789 Replacement Battery 7.74V 2000mAh

Oppo Reno 4 5G — 7.74V Li-Polymer Replacement Battery (BLP789)

This is a 7.74V, 2000mAh Li-Polymer replacement battery for the Oppo Reno 4 5G smartphone. It fits models PDPM00, PDPT00, and CPH2091. Use it to restore a phone suffering from rapid drain, unexpected shutdowns, or a battery that no longer holds a charge.

• Reno 4 5G platform fit (PDPM00 / PDPT00 / CPH2091): These three model codes share the same BLP789 connector pinout and BMS handshake protocol. The fuel gauge IC expects a 7.74V dual-cell Li-Polymer pack — swapping to a single-voltage cell will cause gauge errors and charge cutoffs.
• Bench tested on actual hardware: We ran this cell through full charge cycles on a CPH2091 unit. The BMS accepted the pack without fault flags, and the charge IC stepped through trickle, CC, and CV phases cleanly. No thermal alerts triggered.
• First-cycle calibration tip: On first use after installation, disable VOOC fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins pushing into an uncalibrated state estimation.

Sudden shutdown at 20–30% on the Reno 4 5G after a cell swap

The Reno 4 5G modem draws a sharp current spike during 5G band switching. If the fuel gauge IC is still calibrated to the old cell's discharge curve, it misreads state-of-charge and the phone hits voltage floor before the OS sees 0%. The BMS cuts the load to protect the cell. One full slow-charge cycle re-anchors the coulomb counter to the new cell, and the shutdowns stop.

Phone will not power on after the replacement battery sat in storage

Li-Polymer cells self-discharge during storage. If the cell voltage has dropped below 2.5V per cell, the BMS enters lockout mode and blocks all load output — the phone appears completely dead. Connect the phone to a 5V/1A charger for 20–30 minutes without pressing the power button. This trickle current is enough to lift the cell above the BMS re-enable threshold. Once the screen shows a charge indicator, normal charging can resume.