Tegra 4 Replacement Battery 3.7V 1800mAh Li-ion

Tegra 4 — 3.7V Li-ion 1800mAh Replacement Battery

This is a 3.7V Li-ion cell rated at 1800mAh (6.66Wh), built as a direct swap for the Tegra 4 smartphone. No OEM part number is published for this battery — compatibility is confirmed by voltage, physical dimensions (72.74 × 53.41 × 4.67mm), and connector pinout. Install it when the original cell no longer holds a usable charge through a full day of normal use.

• Tegra 4 fit confirmation: The Tegra 4 runs a single-cell 3.7V architecture. Any replacement cell must match voltage, physical footprint, and the BMS communication protocol — a mismatch on any of these will prevent the charge IC from accepting the cell or trigger an immediate safety cutoff.
• Bench tested on actual hardware: We cycled this cell through a full charge and discharge sequence on the bench. The BMS handshake completed without error flags, charge termination triggered at the correct cutoff voltage, and no thermal event occurred during the high-current phase.
• Fuel gauge recalibration on first use: After installation, disable fast charging and run one complete discharge-to-charge cycle at standard rate. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — preventing early percentage jumps or false-low shutdowns.

Why the Tegra 4 reports wrong battery percentage after a cell swap

The fuel gauge IC stores a learned discharge curve from the old cell. When a new cell goes in, that stored curve no longer reflects actual capacity. The IC reads voltage and compares it to the old curve, so it reports percentages that don't match real charge state. One full discharge-charge cycle at standard rate forces the IC to recalibrate against the new cell's actual voltage profile.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — typically during screen-on, modem bursts, or GPS activity — faster than the fuel gauge IC predicts. The protection circuit trips before the displayed percentage reaches zero. The root cause is the gauge IC still running an uncalibrated curve. Run two full discharge-charge cycles and confirm the shutdown moves closer to 5% or below, which indicates the voltage cliff is now correctly mapped.