LG TM250 Replacement Battery 3.7V 1000mAh LGLI-ACGM

LG TM250 / VX3100 — 3.7V Li-ion Replacement Battery (LGLI-ACGM)

This is a 3.7V, 1000mAh Li-ion replacement battery for the LG TM250, VX3100, and 3100 mobile phones. It replaces OEM part numbers LGLI-ACGM and SBPL0066901. Fit it when the original cell no longer holds a charge through a normal day of use.

• TM250, VX3100, and 3100 compatibility: These three models share the same battery bay dimensions, connector pinout, and 3.7V single-cell architecture. One cell fits all three without any adapter or modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the TM250 platform. The BMS accepted charge current correctly, protection circuitry responded to over-discharge cutoff at the expected threshold, and the phone booted cleanly after each cycle.
• Fuel gauge recalibration on first use: On first installation, disable fast charging if your charger supports it and run one full discharge-charge cycle at standard current. The fuel gauge IC on these LG handsets calibrates its coulomb counter against the cell's actual discharge curve — skipping this step causes the OS to read inaccurate percentages until it completes a full cycle naturally.

Sudden shutdown at 20–30% on the LG TM250 after a cell swap

This is a voltage cliff problem, not a capacity problem. When the modem transmits or the screen peaks, current draw spikes sharply. A new cell that hasn't completed a calibration cycle can sag below the BMS cutoff threshold — roughly 3.0V — even while the fuel gauge still shows charge remaining. The phone interprets that voltage drop as a dead cell and shuts down immediately. One full discharge-charge cycle at standard current resolves this by letting the fuel gauge map the real voltage-to-capacity curve of the new cell.

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

Li-ion cells self-discharge in storage. If the replacement cell dropped below approximately 2.5V before installation, the BMS enters a lockout state and blocks normal charge current to prevent damage. The phone will show no charge indicator and won't power on. Connect it to a wall charger — not a USB port — and leave it for 20–30 minutes without attempting to boot. Most BMS circuits on these LG cells accept a trickle pre-charge at low voltage before releasing the lockout and allowing full charge current to flow.