Soundmaster TR150WS Replacement Battery 3.7V 1000mAh

Soundmaster TR150WS — 3.7V Li-ion Replacement Battery

This is a 3.7V, 1000mAh Li-ion cell built to replace the original battery in the Soundmaster TR150WS. The TR150WS is a compact portable radio with a built-in rechargeable cell — when that cell degrades, the device loses charge retention fast. This replacement matches the original voltage rail and physical footprint at 53.00 × 33.90 × 5.70mm.

• TR150WS fit confirmation: The TR150WS uses a single-cell 3.7V Li-ion pack on a straightforward charge circuit. This cell matches the voltage rail and connector orientation — no adapter or modification needed.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the TR150WS charge circuit and confirmed the BMS accepted charge without triggering overcurrent cutoff. Cell voltage at full charge landed at 4.19V — within spec.
• First-cycle recalibration on the TR150WS: On first use after installation, disable fast charging if the device supports it and run one full discharge-charge cycle. This lets the fuel gauge IC recalibrate its coulomb counter against the new cell's discharge curve before it reports accurate percentages.

Sudden shutdown at 20–30% on the TR150WS after cell swap

This happens because the fuel gauge IC is still running the discharge curve it learned from the old, degraded cell. The new cell has a steeper voltage drop near the end of discharge, and the gauge misreads remaining capacity. When the device hits a load spike — speaker output or a tuner scan — the cell voltage sags below the shutdown threshold before the gauge catches it. Run two full discharge-charge cycles and the IC will remap to the new cell's actual curve.

TR150WS showing incorrect battery percentage after replacement

The fuel gauge IC stores a learned capacity model tied to the old cell. A fresh cell with higher impedance than the aged original will confuse the coulomb counter, causing percentage jumps or a reading that stalls at one number for extended use. This is not a fault with the replacement cell — it is the IC recalibrating. Charge fully to 4.2V, run down to auto-shutoff, then charge fully again to reset the learned curve.