AK-C145 TELME C145 Replacement Battery 3.7V 900mAh

TELME C145 / C145B — 3.7V Li-ion Replacement Battery (AK-C145)

This is a 3.7V, 900mAh Li-ion cell for the TELME C145 and C145B mobile phones. It replaces the original AK-C145 battery when the existing cell no longer holds charge through normal use. Dimensions are 46.47 × 39.79 × 5.33mm — confirm your original before fitting.

• C145 and C145B compatibility: Both models share the same battery bay dimensions, connector pinout, and charge IC voltage thresholds. One cell covers both variants without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the C145 platform. The BMS responded correctly to the phone's charge termination signal and held float voltage without drift at full capacity.
• Fuel gauge recalibration on first use: On first use after fitting, run one full discharge down to automatic shutdown, then charge uninterrupted to 100%. This gives the phone's fuel gauge IC a complete discharge curve to reference — without it, percentage readings can jump or cut off early.

Why the C145 reports wrong battery percentage after a cell swap

The C145 uses a fuel gauge IC that builds its capacity model from observed discharge curves. When you fit a new cell, the IC is still calibrated to the old cell's degraded curve. It will misread state-of-charge until it completes at least one full cycle on the new cell. Percentage jumps of 10–15% in either direction are normal in this recalibration window. Run a full discharge-to-shutdown followed by a full charge and the readings stabilise.

Sudden shutdown at 20–30% on the replacement cell

This happens when the fuel gauge IC's stored discharge curve doesn't match the new cell's actual voltage profile. The phone interprets a voltage drop — caused by modem or backlight load — as a depleted cell and cuts power before the real charge is gone. It is not a fault with the cell itself. Force one complete cycle: discharge until the phone shuts off on its own, then charge to 100% at standard current, and the shutdowns stop once the IC locks onto the correct voltage-to-capacity relationship for the new cell.