Binatone SpeakEasy 600 Replacement Battery 3.7V 1300mAh

Binatone SpeakEasy 600 — 3.7V Li-ion Replacement Battery (HZTBL-4D-01)

This is a 3.7V, 1300mAh Li-ion battery for the Binatone SpeakEasy 600 mobile phone. It replaces OEM part HZTBL-4D-01 directly. Fit this when the original cell no longer holds charge or fails to power the handset through normal use.

• SpeakEasy 600 fit: The SpeakEasy 600 uses a fixed 3.7V single-cell Li-ion architecture with a dedicated connector and BMS handshake matched to this cell. The HZTBL-4D-01 footprint — 60.00 × 43.80 × 4.50mm — is specific to this handset and will not seat correctly in other models.
• Bench tested on actual hardware: We ran this cell through charge, discharge, and re-charge cycles on the SpeakEasy 600. The BMS accepted the cell without fault flags, and the charge IC completed a full cycle to 4.2V cutoff without thermal events.
• Fuel gauge recalibration on first use: After fitting, disable any fast-charge mode and run one complete discharge-to-charge cycle at standard rate. This lets the fuel gauge IC map the new cell's discharge curve before high-current charging begins — skipping this step causes the percentage readout to drift for several days.

Sudden shutdown at 20–30% on the SpeakEasy 600

This is a voltage cliff problem, not a capacity fault. Under modem load or screen-on draw, the cell voltage drops sharply below what the fuel gauge IC predicted — the phone reads 25% but the real cell voltage has already crossed the BMS cutoff threshold. It happens when the gauge is still calibrated to the old, degraded cell curve. Run one full discharge cycle from 100% to automatic shutdown, then charge to 100% without interruption. After that single cycle, the coulomb counter resets its reference and the shutdowns stop.

Phone won't power on after the replacement battery sat in storage

Li-ion cells self-discharge in storage. If this battery was stored below approximately 2.5V per cell, the BMS enters lockout mode and blocks current flow to protect the cell from damage. The phone will show nothing — no boot, no charge indicator. Connect the charger and leave it for 15–20 minutes without pressing any buttons; the charge IC trickle-charges the cell back above the BMS re-enable threshold. Once the voltage clears roughly 2.9V, the BMS releases and normal charging resumes.