Cricket U102AC Replacement Battery 3.7V 1300mAh Li-ion

Cricket U102AC / Debut Flip — 3.7V Li-ion Replacement Battery (TL14H504357W)

This is a 3.7V, 1300mAh Li-ion replacement battery for the Cricket U102AC and Debut Flip mobile phones. It slots in where the original TL14H504357W battery sits and restores power to the device. Capacity is 4.81Wh at the rated voltage.

• U102AC and Debut Flip compatibility: Both models share the same battery bay dimensions (57.50 × 43.00 × 4.80mm), connector pinout, and charge IC handshake — one cell covers both. The BMS communicates over the same two-wire interface on each platform.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the U102AC. The BMS accepted the charge IC handshake on the first cycle, protection thresholds tripped correctly at low voltage, and the fuel gauge IC tracked state of charge without resetting mid-cycle.
• Fuel gauge recalibration on first use: After fitting this cell, disable any fast-charge option for the first complete discharge-charge cycle. The fuel gauge IC on these phones calibrates its coulomb counter against the new cell's discharge curve — running a slow first cycle gives it accurate reference data before high-current charging begins.

Sudden shutdown at 20–30% on the U102AC after a cell swap

This happens because the fuel gauge IC still holds the discharge curve from the old, degraded cell. When the modem or screen pulls a load spike, the new cell's actual voltage drops below the shutdown threshold before the reported percentage catches up. The phone cuts out even though the displayed charge looks fine. One full discharge-to-shutdown followed by an uninterrupted charge to 100% rewrites the coulomb counter and clears the mismatch.

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

Li-ion cells self-discharge during storage. If the TL14H504357W cell drops below roughly 2.5V per cell, the BMS trips a deep-discharge lockout and blocks current flow to protect the cell. The phone will appear completely dead — no logo, no vibration. Connect it to a wall charger for at least 15–20 minutes before attempting to power on; most BMS circuits require a trickle pre-charge phase before they release the lockout and allow normal boot.