AudioVox BTR-8200 CDM-8200 Replacement Battery 3.7V 1000mAh

AudioVox CDM-8200 — 3.7V Li-ion Replacement Battery (BTR-8200)

This is a 3.7V, 1000mAh Li-ion replacement battery for the AudioVox CDM-8200 mobile phone. It replaces OEM part number BTR-8200 directly. If the original cell no longer holds charge or the phone shuts down unexpectedly, this is the direct swap.

• CDM-8200 cell fitment: The CDM-8200 uses a single-cell 3.7V nominal Li-ion pack with a hard-shell housing and a three-contact connector. The BMS handshake on this platform is minimal — voltage and thermistor pin only — so cell compatibility comes down to matching voltage rails and connector pinout, both of which this battery matches.
• Bench tested on actual hardware: We ran this cell through charge and discharge cycles on the CDM-8200 platform. The BMS accepted the cell without fault flags, the thermistor pin read correctly, and charge termination triggered at the expected 4.2V cutoff.
• Fuel gauge recalibration on first use: After installation, run one full discharge down to auto-shutoff, then charge uninterrupted to 100%. The CDM-8200's fuel gauge IC is calibrated to the original cell's discharge curve — skipping this step causes the percentage meter to track the old curve and report incorrect readings against the new cell.

Why the CDM-8200 reports wrong battery percentage after a cell swap

The CDM-8200 uses a fuel gauge IC that tracks capacity against a stored discharge curve from the original cell. When a new cell goes in, that curve no longer matches the actual voltage-to-capacity relationship of the replacement. The gauge reads voltage and maps it against outdated reference data, so 60% displayed may actually be 40% remaining. One full discharge-to-shutoff followed by an uninterrupted charge resets the coulomb counter and lets the IC build a new reference curve against the replacement cell.

Sudden shutdown at 20–30% on the CDM-8200

This is a voltage-cliff issue, not a capacity defect. When the CDM-8200 fires the modem for a call or peaks the backlight, current draw spikes sharply. If the cell voltage sags below the BMS low-voltage cutoff under that load — even briefly — the protection circuit trips and the phone shuts off, even though the gauge still shows charge remaining. On a new cell this usually means the fuel gauge hasn't recalibrated yet. Run one full cycle first. If shutdowns continue after calibration, check that the battery connector contacts are fully seated — a high-resistance connection amplifies voltage sag under load.