About this replacement
Technaxx TX-75 / Sender TX-75 — 3.7V Li-ion Replacement Battery (4652)
This is a 3.7V 10050mAh Li-ion replacement battery for the Technaxx TX-75 and Sender TX-75 wireless home security cameras, also covering the 4648 unit. It matches the OEM part number 4652 and slots into the same physical bay as the original cell. Use it to restore a camera that no longer holds charge or powers on.
- TX-75 / 4648 platform fit: These models share the same 3.7V single-cell architecture, connector pinout, and BMS handshake protocol — which is why one battery covers all three variants listed above.
- Bench tested on actual hardware: We cycled this cell through full charge and discharge passes while monitoring BMS cutoff thresholds. The protection circuit tripped correctly at low-voltage limits and accepted charge without skipping the CC/CV transition.
- First-install power cycle: After fitting this battery, run a manual power cycle through the Technaxx app. The camera firmware must re-register an active cell before motion-event recordings log correctly to cloud storage — skipping this step can cause missed clips even when the camera appears online.
TX-75 going offline in the app after a battery swap
When the TX-75 loses power completely during a battery change, the firmware drops its active session token with the cloud server. The camera comes back on but the app shows it as offline or unresponsive. This is not a battery fault — it is a session registration issue triggered by the power interruption. Open the Technaxx app, remove the device from your account, and re-add it to force a fresh token handshake.
App reporting 0% or wrong battery percentage after install
The TX-75 uses a voltage-threshold indicator, not a fuel-gauge IC, so the percentage reading is derived from resting cell voltage rather than tracked capacity. A freshly installed battery may read 0% or jump erratically until the camera samples a stable resting voltage. Run one full charge cycle through the included charger or solar input until the charge indicator confirms full. After that single cycle the voltage thresholds recalibrate and the percentage display tracks correctly — expect the reading to settle above 3.6V at rest before it shows an accurate figure.