Oppo Realme GT BLP849 Replacement Battery 7.74V 2100mAh

Oppo Realme GT / Realme GT Neo — 7.74V Li-Polymer Replacement Battery (BLP849)

The BLP849 is the original-spec cell for the Realme GT and Realme GT Neo smartphones. This replacement runs at 7.74V with a 2100mAh (16.25Wh) capacity — matching the voltage rail the phone's charge IC and fuel gauge IC expect. It fits both models because they share the same battery bay dimensions, connector pinout, and BMS handshake protocol.

• Realme GT and GT Neo compatibility: Both phones use the same 84.64 × 63.00 × 5.30mm footprint and the same four-pin connector with NTC thermistor line. The BMS on this cell communicates charge state over that same pin arrangement, so the phone's charge IC accepts it without flagging an unrecognised cell.
• Bench tested on actual hardware: We ran this cell through charge cycles on a Realme GT unit. The BMS held cutoff at the expected high-voltage limit, the NTC thermistor reported correctly to the charge IC, and fast-charge handshake initialised on the second cycle after a full calibration discharge.
• Fuel gauge recalibration on first use: On first installation, disable fast charging and run one full discharge-charge cycle at standard rate. The fuel gauge IC is still calibrated to the old cell's discharge curve. Running a slow cycle first lets the coulomb counter map the new cell before high-current charging begins pushing current into an uncalibrated state of charge model.

Why the Realme GT shuts down suddenly at 20–30% after a cell swap

A new Li-Polymer cell has a slightly different voltage-versus-capacity curve than the aged cell it replaces. The phone's fuel gauge IC still holds the old curve in memory. When the modem fires a high-current burst or the screen peaks at full brightness, the actual cell voltage drops faster than the IC predicts — crossing the hardware cutoff threshold while the display still reads 25%. This is a calibration gap, not a faulty cell. One full slow discharge to automatic shutdown, followed by a full charge, rewrites the coulomb counter's reference curve and eliminates the early cutoff.

USB-PD or VOOC fast charge not activating on the replacement cell

Realme's proprietary fast-charge protocol requires the charger adapter, the USB cable, and the phone's charge IC to complete a handshake — but a freshly installed cell with an uncalibrated BMS can cause the charge IC to default to standard 5V charging on the first cycle. This is a protective behaviour, not an incompatibility. Charge the phone fully at standard rate on the first cycle, then reboot before connecting the fast charger again. The charge IC re-attempts the VOOC handshake once the BMS has reported a valid charge state above 3.6V per cell.