LG Gray C800 Replacement Battery BL-48LN 3.7V 1200mAh

LG Gray C800 / Optimus Elite Series — 3.7V Li-ion Replacement Battery (BL-48LN)

This is a 3.7V, 1200mAh Li-ion cell built to the BL-48LN spec. It fits the LG Gray C800, LS696, VM696, Optimus Elite, and over a dozen related models that share the same battery bay dimensions and connector pinout. Capacity figure comes from the product data — 4.44Wh.

• C800 / LS696 / VM696 platform compatibility: These models share the same 52 × 50 × 5.20mm bay, the same three-pin connector, and the same BMS handshake protocol — one cell spec covers the whole family without modification.
• Bench tested on actual hardware: We ran the BL-48LN through charge and discharge cycles on the C800 platform. The BMS accepted the cell, protection thresholds tripped correctly at both ends, and the OS recognised the battery without error codes.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before the charge IC pushes high current into an uncalibrated cell.

Why the C800 reports wrong battery percentage after a cell swap

The C800 uses a fuel gauge IC that builds its charge model against the old cell's impedance and discharge curve. A new cell has different internal resistance, so the IC's coulomb counter starts off-target. The phone may show 40% and then jump to 60%, or report full charge well before the cell is actually topped up. One complete discharge below 10% followed by a full uninterrupted charge resets the calibration window and brings the percentage readings back in line.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff problem, not a capacity problem. When the modem fires a high-power transmission burst or the screen peaks brightness, current draw spikes and the cell voltage drops sharply. If the fuel gauge IC still thinks the cell behaves like the old degraded unit, it sets the low-voltage cutoff threshold too close to that cliff. The BMS trips and the phone shuts off even though the percentage still shows double digits. Run one full calibration cycle first — discharge to auto-off, then charge uninterrupted to 100% — and the cutoff threshold repositions to match the new cell's actual 3.4V floor.