GSmart Roma R2 Replacement Battery 3.7V 1400mAh Li-ion

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

This is a 3.7V, 1400mAh Li-ion cell for the GSmart Roma R2 smartphone. It replaces the original R2 battery when the factory cell has degraded and can no longer hold a usable charge. Dimensions are 65.00 × 48.05 × 4.50mm — same form factor as the OEM unit.

• Roma R2 fit: The R2 part number covers both Roma R2 variants listed in the fit data. The connector pinout, physical dimensions, and voltage rail match the original cell, so the phone's charge IC accepts the swap without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a Roma R2 unit. The BMS accepted charge from the stock charger on the first connection, and the protection circuit tripped correctly at low-voltage cutoff during deep discharge.
• Fuel gauge recalibration on first use: On first use after installation, disable fast charging if your charger supports it and run one full discharge-charge cycle at standard rate. This lets the fuel gauge IC build an accurate discharge curve against the new cell before the OS starts reading percentage from it.

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

This is a voltage cliff failure, not a capacity problem. Under peak modem or screen load, the new cell's internal resistance causes a momentary voltage drop that falls below the BMS cutoff threshold — the phone shuts down even though the fuel gauge still shows charge remaining. It happens most often during calls or video playback because those loads spike current demand faster than the fuel gauge IC can track. Running one full discharge-charge cycle at standard rate brings the coulomb counter into alignment with the actual cell curve and reduces these events significantly.

Roma R2 not powering on after battery sat in storage

Li-ion cells self-discharge during storage. If the cell voltage drops below approximately 2.5V, the BMS enters lockout and blocks normal charge current to protect the cell. The phone will show nothing on screen when you press power. Connect it to the original wall adapter — not a PC USB port — and leave it for 15–20 minutes before attempting to power on. The charge IC on the Roma R2 delivers a trickle recovery current that brings the cell back above the BMS re-enable threshold, typically around 3.0V.