T-Mobile Revvl 4 Plus Compatible Battery TLP038D7 3.85V 3850mAh

T-Mobile Revvl 4 Plus — 3.85V Li-Polymer Replacement Battery (TLP038D7)

This is a 3850mAh Li-Polymer cell at 3.85V, built to replace the original TLP038D7 battery in the T-Mobile Revvl 4 Plus (models 5062W and 5062Z). It fits phones that have lost capacity after extended use or stopped holding a charge. Dimensions are 83.10 × 62.68 × 4.30mm — match these before installation.

• Revvl 4 Plus 5062W and 5062Z compatibility: Both model variants share the same battery bay geometry, connector pinout, and BMS handshake protocol — one cell fits both without modification.
• Bench tested on actual hardware: We cycled this cell through charge and discharge on the 5062 platform. The BMS accepted the cell on first connect, voltage held stable under screen-on and modem load, and charge termination triggered correctly at 4.35V.
• Fuel gauge recalibration after swap: On first use after installation, disable fast charging and run one full discharge-charge cycle at standard current. This allows the fuel gauge IC to recalibrate its coulomb counter against the new cell's discharge curve before high-current charging begins.

Sudden shutdown at 20–30% on the Revvl 4 Plus after a cell swap

A new Li-Polymer cell has a slightly different voltage-to-capacity curve than the aged original. The fuel gauge IC still uses the old curve, so it reads 25% remaining when the actual cell voltage has already dropped below the modem's minimum threshold. Under a burst of LTE traffic or screen wake, the voltage sags further and the phone shuts down. One full discharge-charge cycle resets the coulomb counter and brings the reported percentage back in line with actual cell state.

USB fast charge not activating on the first cycle after replacement

On the first charge cycle after installation, the charge IC may default to trickle or standard current until it verifies the new cell's internal resistance and temperature profile. This is a BMS protection step, not a fault. Do not assume the cable or charger is defective. Complete one full standard-rate charge cycle — fast charge negotiation typically resumes normally from the second cycle onward.