T-Mobile Revvl 5G Replacement Battery TLP043E7 3.85V

T-Mobile Revvl 5G — 3.85V Li-Polymer Replacement Battery (TLP043E7)

This is a 3.85V, 4250mAh Li-Polymer cell for the T-Mobile Revvl 5G smartphone. It replaces OEM part TLP043E7 when the original cell has degraded, swells, or can no longer hold a charge. Dimensions are 78.54 × 63.00 × 4.95mm — confirm clearance before installation.

• Revvl 5G cell compatibility: The Revvl 5G uses a 3.85V nominal Li-Polymer architecture with a single-cell BMS that negotiates directly with the Qualcomm charge IC. Any replacement must match that voltage rail and connector pinout exactly — this cell does.
• Bench tested on actual hardware: We cycled this cell through full charge and discharge on the Revvl 5G platform. The BMS handshake completed without error flags, and the charge IC accepted current at both standard and fast-charge rates after the first full cycle.
• Fuel gauge recalibration on first cycle: On first use after installation, disable fast charging and run one complete discharge-to-charge cycle. This allows the fuel gauge IC to build an accurate discharge curve against the new cell before high-current charging begins on an uncalibrated coulomb counter.

Sudden shutdown at 20–30% on the Revvl 5G after a cell swap

The Revvl 5G's fuel gauge IC retains the discharge curve of the old, degraded cell after replacement. When the new cell hits a voltage point the IC associates with a higher state-of-charge, it misreads remaining capacity. Under modem or display load, the cell voltage drops briefly below the BMS cutoff threshold — typically around 3.2V — triggering an abrupt shutdown even though the percentage display shows charge remaining. One full discharge-charge cycle without fast charging resets the coulomb counter and resolves this.

USB-PD fast charge not accepted on the first cycle after replacement

On the first charge after installation, some units show the Revvl 5G falling back to standard 5W charging rather than accepting fast charge negotiation. The charge IC runs a brief impedance check on the new cell before allowing elevated current — this is normal BMS behaviour, not a fault. Let the first cycle complete at standard rate, then reconnect with the fast charger. Fast charge should activate from the second cycle onward once the IC has profiled the new cell's internal resistance.