About this replacement
AudioVox CDM-130 / CDM-8100 Series — 3.7V Li-ion Replacement Battery
This 3.7V, 1000mAh Li-ion battery fits the AudioVox CDM-130, CDM-135, CDM-8100, and CDM-8150 handsets. It replaces the original cell when the phone no longer holds a charge through a full day of use. Capacity and voltage match the factory spec — 3.7V nominal, 3.7Wh total energy.
- CDM-130, CDM-135, CDM-8100, CDM-8150 fit range: These four models share the same battery bay geometry, connector pinout, and 3.7V single-cell architecture. One cell covers all four without modification.
- Bench tested on actual hardware: We cycled this cell through charge and discharge on the CDM-8100 platform. The BMS accepted the charge current without tripping, and the protection circuit held cutoff at the correct low-voltage threshold.
- Fuel gauge recalibration on first use: After installing this cell, run one complete discharge to auto-off, then charge uninterrupted to 100% before normal use. The CDM series fuel gauge IC maps its percentage readings against the discharge curve — skipping this step causes the percentage counter to drift against the new cell from day one.
Why the CDM-130 reports wrong battery percentage after a cell swap
The CDM-130 uses a coulomb-counting fuel gauge IC that builds its percentage model from the discharge curve of the installed cell. When you swap in a new cell, that learned curve no longer matches reality. The gauge continues reporting against old data until it runs a fresh full cycle. One complete discharge-to-cutoff followed by a full uninterrupted charge resets the reference curve and brings the percentage readout back into line.
Sudden shutdown at 20–25% on the CDM-8100 and CDM-8150
This is a voltage cliff failure, not a capacity problem. When the cell voltage drops below roughly 3.4V under the load of the radio transmitter, the protection circuit trips and cuts power — even though the fuel gauge still shows charge remaining. It happens because the fuel gauge percentage and the real cell voltage are out of sync. Run one full calibration cycle as described in the care tip above, and the shutdowns stop once the gauge learns where the actual voltage floor sits.