AK-C150 Emporia Telme C150 Compatible Battery 3.7V 900mAh

Emporia Telme C150 / C151 / T200 — 3.7V Li-ion Replacement Battery (AK-C150)

This is a 3.7V, 900mAh lithium-ion battery that replaces the original AK-C150 cell in the Emporia Telme C150, Telme C151, and Telme T200 mobile phones. It restores power to a phone that no longer holds enough charge for calls and basic messaging. Capacity figure is 900mAh (3.33Wh) — matching the original cell specification.

• Telme C150, C151, and T200 compatibility: All three models use the same battery bay dimensions, connector pinout, and 3.7V nominal rail, so a single cell — AK-C150 — fits across the range without modification or adapters.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the Telme platform and confirmed the BMS handshake completes correctly, charge termination triggers at the expected voltage, and the phone does not flag a battery error on boot.
• Fuel gauge recalibration on first use: After fitting this cell, run one full discharge down to automatic shutdown, then charge uninterrupted to 100% before normal use. The Telme's fuel gauge IC was calibrated to the old cell's discharge curve — skipping this step causes erratic percentage readings from day one.

Why the Telme C150 reports wrong battery percentage after a cell swap

The Telme C150 uses a coulomb-counting fuel gauge IC that builds its capacity model from discharge data accumulated on the original cell. When a new cell goes in, that learned model no longer matches the actual discharge curve of the replacement. The phone reads a voltage that maps to, say, 40% on the old curve — but the new cell at that same voltage may have 60% remaining. One full uninterrupted discharge-to-shutdown followed by a complete charge resets the reference point and lets the gauge relearn against the new cell.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — typically during a call, where the modem draws a short high-current spike — even though the resting voltage looked fine seconds earlier. A worn or newly installed cell with a slightly higher internal impedance will sag past the BMS undervoltage cutoff threshold (typically 3.0V per cell) under that load spike while the display still shows 25%. The fix is to complete the fuel gauge recalibration cycle first: a full discharge and uninterrupted recharge to 100%. After that cycle the gauge maps percentage to actual usable voltage range and the phone cuts off closer to true 0% rather than an uncalibrated cliff.