AudioVox BTR-8030 Replacement Battery 3.7V 800mAh Li-ion

AudioVox PCD TXT8030 / TXT8030 Razzle — 3.7V Li-ion Replacement Battery (BTR-8030)

This is a 3.7V, 800mAh Li-ion replacement battery for the AudioVox PCD TXT8030 and TXT8030 Razzle mobile phones. It replaces OEM part numbers BTR-8030 and BTR-8030B. If your original battery no longer holds a charge through a normal day of calls and messages, this cell restores the phone to its original power spec.

• TXT8030 and TXT8030 Razzle compatibility: Both variants use the same 3.7V single-cell Li-ion battery bay, identical connector pinout, and the same BMS handshake protocol — so one cell covers both models without any modification.
• Bench tested on actual hardware: We ran this cell through full charge and discharge cycles on the TXT8030 platform. The BMS accepted the cell without fault codes, and charge termination triggered correctly at 4.2V per cell.
• Fuel gauge recalibration on first use: On first use after installation, disable any fast-charge option for one complete discharge-charge cycle. This lets the phone's fuel gauge IC learn the new cell's discharge curve before high-current charging begins on an uncalibrated cell.

Sudden shutdown at 20–30% on the TXT8030 after a cell swap

The TXT8030 fuel gauge IC stores a discharge model calibrated to the original cell. A new cell with a slightly different internal resistance profile causes the IC to misread remaining voltage. Under modem transmit load or backlight draw, the actual cell voltage drops faster than the gauge predicts, and the phone shuts off before the display reaches 0%. Running one full discharge down to automatic shutdown, then charging uninterrupted to 100%, forces the coulomb counter to resync with the new cell curve. After that cycle, the percentage readings stabilise.

TXT8030 not powering on after sitting in storage with a flat battery

If the cell discharged below 2.5V during storage, the BMS locks out to prevent damage from charging a deeply depleted lithium cell. The phone will show no response — no charge indicator, no boot screen. Connect the phone to a wall charger, not a PC USB port, and leave it for 20–30 minutes without pressing any buttons. A wall adapter supplies enough current for the BMS recovery circuit to trickle the cell back above the 2.9V threshold needed to re-enable normal charging. Once the charge LED activates, the lock has cleared.