Alcatel OT-606 Replacement Battery CAB31C0000C1 3.7V 700mAh

Alcatel OT-606 Series — 3.7V Li-ion Replacement Battery (CAB31C0000C1)

This is a 3.7V, 700mAh Li-ion cell that fits the Alcatel OT-606, OT-606C, OT-606A, and OT-606 Sparq. It replaces the original CAB31C0000C1 (also cross-referenced as OT-BY23) when the existing cell has degraded and can no longer hold adequate charge. Physical dimensions are 37.68 × 37.24 × 5.41mm — measure your original before fitting if you are unsure.

• OT-606 variant coverage: The OT-606, OT-606C, OT-606A, and OT-606 Sparq all share the same battery bay dimensions, voltage rail, and connector pinout. One cell fits the full family without modification.
• Bench tested on actual hardware: We cycled this cell through full discharge-charge sequences and confirmed the BMS communicates correctly with the charge IC — protection cutoffs for overcurrent and over-voltage triggered at expected thresholds.
• Fuel gauge recalibration on first use: After fitting this cell, disable fast charging if your charger supports it, then run one complete discharge down to automatic shutdown followed by a full charge. The fuel gauge IC on the OT-606 calibrates its coulomb counter against the actual discharge curve of the new cell on that first cycle — skipping this step causes erratic percentage readings.

Sudden shutdown at 20–30% on the OT-606 after a cell swap

The OT-606's fuel gauge IC retains the discharge curve of the old, degraded cell after a swap. When the new cell's actual resting voltage no longer matches the IC's stored curve, the phone misreads remaining capacity. Under modem or screen load — both are high-current draws for a 700mAh cell — the battery voltage dips sharply, and the phone hits its hardware undervoltage cutoff before the OS registers low battery. Run one full discharge-charge cycle without interruption. After that cycle, the coulomb counter resets to the new cell's actual curve and the premature shutdowns stop.

OT-606 not powering on after the replacement battery sat in storage

Li-ion cells self-discharge in storage. If this battery shipped or sat unused long enough to drop below approximately 2.5V, the BMS enters lockout mode to prevent cell damage — the phone will show no signs of life when you press the power button. Connect the phone to a wall charger, not a USB port, and leave it for 20–30 minutes without pressing any buttons. The charge IC trickle-charges the cell back above the BMS re-enable threshold, typically around 2.9V, at which point normal charging resumes and the phone powers on.