Beeline Pro 3.8V Replacement Battery 2300mAh Li-ion

Beeline Pro — 3.8V Li-ion 2300mAh Replacement Battery

This 3.8V Li-ion cell is a direct swap for the battery in the Beeline Pro smartphone. It carries 2300mAh (8.74Wh) of capacity and fits the original battery cavity at 66.60 × 50.20 × 5.30mm. Use it when the original cell no longer holds enough charge to get through a normal day.

• Beeline Pro fit: The Beeline Pro uses a 3.8V nominal Li-ion cell with a specific connector pinout and BMS handshake. This cell matches that voltage rail and physical footprint, so the phone's charge IC can communicate with it correctly.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a controlled bench rig. The BMS responded correctly at both the low-voltage cutoff threshold and the full-charge termination point, with no rogue current events during the charge ramp.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC build a fresh discharge curve against the new cell before high-current charging pushes electrons into an uncalibrated counter.

Why the Beeline Pro reports wrong battery percentage after a cell swap

The Beeline Pro uses a coulomb-counting fuel gauge IC that tracks charge by integrating current over time against a stored discharge curve. When you swap the physical cell, the IC still references the old curve — so the percentage it reports no longer maps accurately to the new cell's actual state of charge. The fix is one full uninterrupted discharge down to automatic shutdown, followed by a full charge to 100% without interruption. After that single cycle the fuel gauge recalibrates its endpoints and percentage reporting stabilises.

Sudden shutdown at 20–30% on the replacement cell

This happens when the modem or screen pulls a high instantaneous current and the cell voltage sags below the phone's hardware cutoff threshold — even though the fuel gauge still shows charge remaining. It is a voltage cliff issue, not a capacity issue. The cell may be partially discharged from storage, or the fuel gauge has not yet calibrated the new cell's internal resistance. Run one full calibration cycle first; if shutdowns continue after that, check that the cell resting voltage is at or above 3.7V before use.