Gigabyte gSmart UBI-4-1300 Replacement Battery 3.7V 1700mAh

Gigabyte gSmart — 3.7V Li-ion Replacement Battery (UBI-4-1300)

This is a 3.7V, 1700mAh Li-ion replacement battery for the Gigabyte gSmart smartphone. It fits the gSmart line directly, restoring power when the original cell has degraded past useful capacity. Rated at 6.29Wh — match this figure against your current battery label before installing.

• gSmart platform fit: The gSmart series shares a common battery bay and connector across its early touchscreen handsets. The UBI-4-1300 cell matches that footprint — same contact orientation, same voltage rail — so the charge IC recognises it without negotiation.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on a gSmart unit. The BMS accepted charge from cold, held the 3.7V nominal rail through mid-cycle, and tripped the protection circuit cleanly at the low-voltage cutoff floor rather than dropping abruptly.
• 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 the new cell's discharge curve before high-current charging runs against an uncalibrated coulomb counter — which is what causes early erratic percentage readings.

Why the gSmart reports wrong battery percentage after a cell swap

The fuel gauge IC stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches real cell behaviour — the IC is measuring against the wrong reference. You'll see the percentage jump, stall, or read high until the phone runs at least one full uninterrupted cycle. A full discharge to auto-shutdown followed by a charge to 100% without interruption resets the coulomb counter against actual cell capacity. After one cycle, percentage accuracy normalises.

Sudden shutdown at 20–30% on the replacement cell

This is a voltage cliff, not a capacity problem. At around 20–30% state-of-charge, the cell's internal resistance rises enough that screen or modem load pulls voltage below the 3.0V protection threshold — the BMS cuts output instantly. It looks like a crash but the battery is actually responding correctly. The fix is the same full calibration cycle: run the phone down to forced shutdown under normal use, then charge uninterrupted to 100%. If shutdowns persist below 3.2V under load after two full cycles, the cell's internal resistance is outside spec and should be returned.