Oppo Reno7 Z 5G BLP907 Replacement Battery 3.87V 4400mAh

Oppo Reno7 Z 5G — 3.87V Li-Polymer Replacement Battery (BLP907)

This is a 4400mAh Li-Polymer replacement battery for the Oppo Reno7 Z 5G (CPH2343). It runs at 3.87V and delivers 17.03Wh — matching the original BLP907 cell specification. Swap it in when the original cell has lost capacity or no longer holds a charge through a full day.

• Reno7 Z 5G / CPH2343 fitment: Both model references share the same PCB layout, connector pinout, and BMS handshake protocol, so this single BLP907-spec cell covers the full variant range without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the CPH2343 board. The BMS accepted the cell, protection circuits triggered correctly at voltage floor, and the charge IC stepped through trickle, CC, and CV phases as expected.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging and run one complete discharge-charge cycle at standard rate. This gives the fuel gauge IC a clean discharge curve to map against the new cell before high-current charging pushes current into an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Reno7 Z 5G

The Reno7 Z 5G runs a 5G modem and high-refresh display simultaneously — both draw hard current spikes. If the cell cannot sustain voltage under that combined load, the protection circuit reads an undervoltage event and cuts power before the OS-reported percentage reaches zero. This is a voltage cliff failure, not a capacity failure. After replacing the battery, complete one full calibration cycle so the fuel gauge IC maps the new cell's actual voltage curve, and the OS percentage will track real cell state accurately.

VOOC fast charge not activating after cell replacement

Oppo's VOOC protocol requires the charge IC to handshake with the battery BMS before stepping up current. On the first cycle after a cell swap, the BMS may not complete that handshake, and the phone falls back to standard 5W charging. This is not a fault — it clears after one full standard-rate charge cycle. Charge to 100% at standard rate using the original VOOC cable, then subsequent sessions will re-engage the fast charge protocol normally.