AudioVox BTR-1 Replacement Battery 3.7V 800mAh Li-ion CDM-7076

AudioVox CDM-7076 — 3.7V Li-ion Replacement Battery (BTR-1)

This is a 3.7V, 800mAh Li-ion cell for the AudioVox CDM-7076 candybar mobile phone. It slots into the original battery compartment and connects to the phone's charge IC and fuel gauge circuit. Voltage and capacity match the BTR-1 OEM specification exactly.

• CDM-7076 fit: The CDM-7076 uses a single-cell 3.7V nominal rail with a three-contact connector — positive, negative, and a thermistor line the charge IC monitors during charge cycles. This cell matches all three contacts and the physical footprint at 54.52 × 35.08 × 4.90mm.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the CDM-7076 platform. The BMS accepted charge without cutoff errors, and the thermistor contact held stable readings throughout — no false overheat flags from the charge IC.
• Fuel gauge recalibration on first use: On first use after installation, run the phone down to auto-shutdown, then charge uninterrupted to 100% before normal use. The CDM-7076's fuel gauge IC calibrates its coulomb counter against this first full cycle — skipping it causes the percentage display to read inaccurately for weeks.

Sudden shutdown at 20–30% on the CDM-7076 after a cell swap

The CDM-7076's processor and RF transmitter draw a combined current spike during calls and network searches. A new cell with a slightly different internal resistance curve can drop below the phone's minimum operating voltage under that load, triggering shutdown even though the fuel gauge still shows charge remaining. This is a voltage-sag issue, not a cell fault. One full discharge-charge calibration cycle tightens the fuel gauge's voltage-to-percentage mapping and typically resolves the early cutoff.

Phone won't power on after the BTR-1 sat in storage

Li-ion cells self-discharge at roughly 2–3% per month. A BTR-1 that has been stored for a year or more can fall below 2.5V — the threshold where the BMS locks out charging to prevent cell damage. The CDM-7076 will show no signs of life and will not respond to the charger. Connect the phone to a wall charger and leave it untouched for 20–30 minutes — the BMS uses a low-current trickle to bring the cell back above 3.0V before allowing normal charge current to flow.