Gigabyte gSmart t600 Replacement Battery 3.7V 1300mAh

Gigabyte gSmart t600 / MW998 — 3.7V Li-ion Replacement Battery (A2K40-EB3010-Z0R)

This is a 3.7V, 1300mAh Li-ion cell for the Gigabyte gSmart t600 and gSmart MW998 smartphones. It replaces part number A2K40-EB3010-Z0R and GPS-H01. Physical dimensions are 63.94 × 39.15 × 6.10mm — measure your original before ordering if you are unsure.

• gSmart t600 and MW998 compatibility: Both models share the same battery bay dimensions, connector pinout, and 3.7V voltage rail, which is why one cell covers both. The BMS handshake is identical across the pair, so no firmware flags are triggered on swap.
• Bench tested on actual hardware: We ran this cell through a full charge and discharge cycle on the gSmart platform. The BMS accepted charge without overcurrent flags, and the protection circuit tripped correctly at the low-voltage cutoff threshold.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge mode and run one complete discharge-to-charge cycle at standard current. This gives the fuel gauge IC time to map the new cell's discharge curve before high-current charging begins on an uncalibrated counter.

Sudden shutdown at 20–30% on the gSmart t600

The gSmart t600's fuel gauge IC was calibrated against the original cell's internal resistance curve. A new cell — even at full capacity — has a different impedance profile. When the modem transmits or the screen brightness peaks, current draw spikes and the cell voltage briefly dips below the shutdown threshold, even though the reported percentage looks safe. The phone reads that voltage drop as a dead battery and cuts power immediately. One full discharge-to-zero followed by an uninterrupted charge to 100% lets the coulomb counter reset against the actual cell curve and resolves most of these false cutoffs.

Phone won't power on after the replacement cell sat in storage

Li-ion cells self-discharge in storage, and if voltage drops below roughly 2.5V per cell the BMS enters a lockout state to prevent damage. Plugging in the charger may show nothing on screen for several minutes — this is normal. Connect a known-good charger and leave it for 15–20 minutes before attempting to power on; the BMS needs a trickle charge to exit lockout before it will pass current to the phone's main board. If the screen remains dark after 30 minutes of charging, check that the charger is delivering at least 5V at the cable tip.