Gigabyte Gsmart Roma R2 Replacement Battery 3.7V 1400mAh

Gigabyte Gsmart Roma R2 — 3.7V Li-ion Replacement Battery (R2)

This is a 3.7V, 1400mAh Li-ion cell for the Gigabyte Gsmart Roma R2 smartphone. It replaces the original internal battery when the phone can no longer hold charge, shuts down unexpectedly, or fails to power on. Dimensions are 65.00 × 48.05 × 4.50mm — verify these against your existing cell before installing.

• Gsmart Roma R2 compatibility: The Roma R2 uses a single-cell 3.7V Li-ion pack with a low-current BMS matched to the phone's charge IC. This cell matches that voltage rail and connector pinout, so the charge IC can communicate with the BMS without throwing a fault.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS reported correct voltage at all three pins, and the charge IC accepted the cell without triggering an authentication reject or thermal fault.
• 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 map its coulomb counter to the new cell's actual discharge curve before higher charge currents are applied to an uncalibrated cell.

Sudden shutdown at 20–30% on the Roma R2 after a cell swap

This happens because the fuel gauge IC is still running the discharge curve from the old, degraded cell. When the new cell hits a voltage point the IC hasn't mapped correctly, the phone treats it as a critical low-voltage event and shuts down — even though the cell has charge remaining. The fix is a full discharge to below 5% followed by an uninterrupted charge to 100% with the screen off. After one complete cycle, the coulomb counter recalibrates and the reported percentage tracks the actual cell voltage accurately.

Phone stays at the boot logo after deep-discharge storage

If the Roma R2 sat unused for an extended period, the cell may have dropped below 2.5V — the BMS lockout threshold. At that voltage, the BMS disconnects the cell to prevent damage, and the phone cannot draw enough current to complete a boot sequence. Connect the phone to a wall charger rated at 5V/1A and leave it for 20–30 minutes without pressing the power button. The charge IC trickle-charges the cell back above 2.8V, at which point the BMS reconnects and the phone will power on normally.