About this replacement
Oppo Reno 3 5G / Reno 3 5G Aura — 3.85V Li-Polymer Replacement Battery (BLP755)
This is a 3800mAh (14.63Wh) Li-Polymer replacement battery for the Oppo Reno 3 5G and Reno 3 5G Aura smartphones. It uses OEM part number BLP755 and fits the PCLM50 and PDCT00 board variants. Voltage is 3.85V nominal — matching the original cell specification exactly.
- Reno 3 5G and Reno 3 5G Aura compatibility: Both the standard and Aura variants use the same BLP755 cell with identical connector pinout, BMS handshake, and 3.85V voltage rail. The PCLM50 and PDCT00 board variants draw from the same charge IC, so one cell covers all four fit models.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the Reno 3 5G platform. The BMS accepted the BLP755 handshake without error flags, and the fuel gauge IC began tracking coulombs from the first cycle without interruption.
- First-cycle fast-charge protocol: On first use after installation, disable VOOC or fast charging and run one complete discharge-charge cycle at standard speed. This lets the fuel gauge IC recalibrate its discharge curve against the new cell before high-current charging pushes into an uncalibrated state.
Why the Reno 3 5G reports wrong battery percentage after a cell swap
The fuel gauge IC in the Reno 3 5G stores a learned discharge curve from the old cell. When a new cell goes in, the IC has no reference for the new cell's actual capacity floor or voltage profile. It keeps reading against stale data, which causes the percentage display to lag, jump, or plateau. One full discharge-charge cycle at standard speed forces the coulomb counter to re-anchor to the new cell's real voltage endpoints.
Sudden shutdown at 20–30% on the replacement cell
This happens when the cell voltage drops sharply under combined modem and display load — a voltage cliff the fuel gauge did not predict. The BMS triggers a hard cutoff to protect the cell before the percentage readout catches up. It is not a defective battery; it is the gauge IC still running the old cell's curve. After two full discharge-charge cycles at standard speed, the fuel gauge re-maps the cliff point and shutdowns at low percentage stop.