Optus X Sleek TLP024C1 Replacement Battery 3.85V 2400mAh

Optus X Sleek / OT-5080Q — 3.85V Li-Polymer Replacement Battery (TLP024C1)

This is a 3.85V, 2400mAh lithium-polymer cell for the Optus X Sleek smartphone (model OT-5080Q / 5080Q). It replaces the original TLP024C1 when the existing cell has degraded past usable capacity. Voltage, footprint, and connector match the original battery bay.

• X Sleek / OT-5080Q platform fit: The 5080Q and X Sleek share the same battery bay dimensions (70.95 × 56.70 × 3.40mm), connector pinout, and BMS communication protocol — one cell covers both model references without modification.
• Bench tested on actual hardware: We ran this cell through a full charge-discharge cycle on the OT-5080Q platform. The BMS accepted the cell on first connection, charge IC engaged normally, and the fuel gauge IC tracked state of charge without manual reset.
• First-cycle fuel gauge recalibration: After fitting this cell, disable fast charging and run one complete discharge-to-charge cycle before returning to normal use. The fuel gauge IC on the 5080Q is calibrated against the old cell's discharge curve — one full cycle lets it map the new cell's characteristics and report accurate percentages.

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

A fresh lithium-polymer cell has a steeper voltage drop-off under peak load than a broken-in cell. When the modem fires a transmission burst or the display ramps brightness, current draw spikes sharply. If the fuel gauge IC still holds the old cell's discharge curve in memory, it reports 25% when the actual terminal voltage under load is already near the BMS cutoff threshold. The BMS trips and the phone shuts down. One full discharge-to-shutdown followed by a full charge resets the coulomb counter and eliminates these early cutoffs.

Phone warm near the battery compartment on the first charge cycle

A new high-impedance lithium-polymer cell dissipates more heat during the initial charge than a conditioned cell does. The charge IC on the OT-5080Q applies the same current it used on the old, lower-impedance cell — so internal resistance losses generate more heat until the cell conditions over the first few cycles. This is normal and reduces after two to three full charge cycles. If the phone becomes hot enough to be uncomfortable to hold, pause charging and let it cool to room temperature before resuming at a lower-current source such as a standard 5W USB adapter.