T-Mobile Accord CAB22D0000C1 Replacement Battery 3.7V 700mAh

T-Mobile Accord — 3.7V Li-ion Replacement Battery (CAB22D0000C1)

This is a 3.7V, 700mAh Li-ion replacement battery for the T-Mobile Accord flip phone. It fits the Accord directly and uses OEM part number CAB22D0000C1. Install it when the original cell no longer holds a charge or the phone shuts down unexpectedly.

• T-Mobile Accord compatibility: The Accord uses a single-cell Li-ion pack at 3.7V nominal with a proprietary form factor — 46.60 x 33.90 x 4.60mm. This replacement matches that footprint and voltage rail exactly, so the phone's charge IC sees the correct cell chemistry without modification.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the bench. The BMS held cutoff correctly at both ends — no overcharge above 4.2V and no undervoltage passthrough below 3.0V. Capacity tracked within expected range of the 700mAh rating.
• Fuel gauge recalibration on first use: After swapping the cell, disable any fast-charge mode if available and run one full discharge-to-charge cycle before regular use. The Accord's fuel gauge IC is calibrated to the old cell's discharge curve — one complete cycle lets it map the new cell and report accurate percentages going forward.

Why the Accord reports wrong battery percentage after a cell swap

The Accord's fuel gauge IC stores a learned discharge curve from the original cell. When you install a new cell, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads voltage and maps it to percentage using outdated data, so it can show 40% when the cell is nearly flat — or 100% before the cell is actually full. One complete discharge down to auto-shutoff followed by a full charge resets the coulomb counter and forces the IC to relearn the new curve.

Sudden shutdown at 20–30% on the replacement cell

This happens when the cell voltage drops sharply under load — a phenomenon called a voltage cliff. During a call, the phone's transmitter draws a short burst of current that the cell cannot sustain, and the voltage collapses below the BMS cutoff threshold even though the gauge still shows charge remaining. It is more pronounced on a new cell before the fuel gauge IC has recalibrated. Run one full discharge-charge cycle first; if shutdowns persist after calibration, check that the battery contacts are clean and making firm contact — dirty contacts add resistance that worsens voltage sag under load.