Pantech BAT-7500M Vega N6 Replacement Battery 3.7V 2500mAh

Pantech Vega N6 / IM-A860 Series — 3.7V Li-ion Replacement Battery (BAT-7500M)

This is a 3.7V, 2500mAh Li-ion cell replacing OEM part BAT-7500M in the Pantech Vega N6 smartphone. It fits the IM-A860, IM-A860L, and IM-A860S variants. Dimensions are 83.05 × 57.00 × 4.85mm — measure your original before installing.

• IM-A860 variant compatibility: The IM-A860, IM-A860L, and IM-A860S share the same physical footprint, connector pinout, and BMS handshake requirements. All three accept BAT-7500M without modification.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the IM-A860 platform. The BMS accepted the new cell without throwing charge faults, and voltage held stable under display and modem load.
• Fuel gauge recalibration on first use: After installation, disable fast charging for the first complete discharge-charge cycle. The Vega N6 fuel gauge IC calibrates its coulomb counter against the discharge curve of the installed cell. Running a slow first cycle gives the IC accurate data before high-current charging begins.

Sudden shutdown at 20–30% on the Vega N6 after a cell swap

The Vega N6 fuel gauge IC builds its state-of-charge map from the previous cell's discharge curve. When a new cell goes in, the stored curve no longer matches actual cell voltage under load. The modem and display draw peaks can pull the cell voltage below the BMS cutoff threshold while the OS still shows 20–30% remaining. One full slow discharge-charge cycle resets the coulomb counter and aligns the fuel gauge to the new cell. After that cycle, shutdowns at false-low percentages typically stop.

Phone stays on the boot screen and won't fully start after storage

If the battery sat discharged for an extended period, the cell voltage may have dropped below 2.5V — the threshold where the BMS locks out to prevent cell damage. The phone draws just enough current to light the screen but cannot sustain the load needed to complete the boot sequence. Connect the phone to a wall charger and leave it untouched for 20–30 minutes before attempting to power on. The charger bypasses the BMS lockout with a trickle current, recovering the cell to a level where normal charging resumes — typically around 3.0V.