TeXet TM-B410 Compatible Battery TB-BL4D 3.7V 1200mAh

TeXet TM-B410 — 3.7V Li-ion Replacement Battery (TB-BL4D)

This is a 3.7V, 1200mAh Li-ion battery for the TeXet TM-B410 mobile phone. It replaces part number TB-BL4D directly. Dimensions are 60.00 × 43.80 × 4.50mm — measure your original before ordering if you are unsure.

• TM-B410 fit: The TM-B410 uses a removable cell with a standardised connector and a simple BMS handshake at 3.7V nominal. No proprietary authentication chip is present, so the replacement cell communicates normally with the phone's charge IC without firmware barriers.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the bench. The BMS held charge termination correctly at 4.2V and triggered low-voltage cutoff cleanly before the cell dropped below safe floor voltage. No thermal events were recorded during the test.
• Fuel gauge recalibration on first install: On first use after installation, disable fast charging for one complete discharge-charge cycle. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging pushes current into an uncalibrated state — preventing erratic percentage readings from the first charge onward.

Why the TM-B410 reports wrong battery percentage after a cell swap

The fuel gauge IC in the TM-B410 stores a learned discharge curve from the original cell. When a new cell goes in, that stored curve no longer matches the actual voltage-to-capacity relationship of the replacement. The phone reads voltage from the cell but maps it against the old calibration, which shifts the reported percentage up or down from reality. One full discharge-to-shutdown followed by a full charge to 4.2V resets the coulomb counter and lets the IC build a new curve against the actual cell.

Sudden shutdown at 20–30% on the TM-B410 after replacement

This is a voltage cliff issue, not a capacity fault. Under screen-on or network load, the cell's internal resistance causes voltage to sag sharply below the phone's minimum operating threshold — even though the gauge still shows charge remaining. The BMS cuts power to protect the cell before the displayed percentage reaches zero. If this happens, run two full unconstrained discharge-charge cycles; if shutdowns persist, check that resting cell voltage reads at least 3.7V on a multimeter before reinstalling.