AudioVox BTR-8915 Replacement Battery 3.7V 850mAh Li-ion

AudioVox CDM-8915 — 3.7V Li-ion Replacement Battery (BTR-8915)

This is a 3.7V, 850mAh Li-ion battery for the AudioVox CDM-8915 mobile phone. It replaces OEM part numbers BTR-8915 and BLI-994-8. If your original battery no longer holds a charge or the phone dies unexpectedly, this cell restores normal operation.

• CDM-8915 fit confirmation: The CDM-8915 uses a 3.7V single-cell Li-ion pack with a three-contact connector — positive, negative, and a BSI (battery status indicator) pin. This replacement matches that connector layout and BSI resistor value so the phone recognises the pack on first boot without throwing a battery fault.
• Bench tested on actual hardware: We cycled this cell through a full discharge and recharge sequence on the CDM-8915 platform. The BMS accepted charge from the phone's internal charge IC without triggering an overvoltage cutoff, and the cell held stable voltage under both voice-call and standby load.
• Fuel gauge recalibration tip: After installing this cell, run one complete discharge down to automatic shutoff, then charge uninterrupted to 100% before normal use. The CDM-8915's fuel gauge IC was calibrated to your old cell's discharge curve — skipping this step causes the percentage meter to read inaccurately for weeks.

Why the CDM-8915 reports wrong battery percentage after a cell swap

The CDM-8915 uses a coulomb-counting fuel gauge IC that tracks charge by measuring current in and out of the cell over time. When the original cell degrades, the phone quietly recalibrates its internal charge map to match a reduced capacity. A new 850mAh cell presents a different discharge curve, so the gauge overestimates depletion early in the cycle and reads as full too quickly. One complete uninterrupted charge-to-100% cycle after the first full discharge forces the IC to rebuild its reference map against the new cell. After that single calibration cycle, percentage accuracy returns to normal.

Sudden shutdown at 20–30% on the replacement cell

This happens when the phone's modem transmit burst pulls current the cell cannot sustain at that state of charge, causing terminal voltage to sag below the BMS cutoff threshold — typically around 3.0V — even though the gauge still shows charge remaining. It is most common in the first few cycles before the fuel gauge IC has mapped the new cell's actual voltage-versus-capacity curve. Run the calibration cycle described above: one full discharge to shutoff followed by an uninterrupted charge to 100%. If shutdowns continue past two full cycles, check that the BSI contact on the battery is clean and making solid contact with the phone's connector pin.