About this replacement
Huawei FreeLace Pro — 3.82V Li-Polymer Replacement Battery (HB411141ECW)
This is a 3.82V, 150mAh Li-Polymer cell for the Huawei FreeLace Pro neckband earbuds, fitting the HUA01 unit. It replaces the original HB411141ECW cell inside one earbud housing. Battery degradation on these earbuds shows up as shortened playback sessions or a unit that stops holding charge entirely.
- FreeLace Pro and HUA01 fitment: Both model designations use the same HB411141ECW cell with identical voltage rail, physical dimensions, and connector orientation. The 40.00 × 10.60 × 3.80mm footprint fills the housing without modification.
- Bench tested on actual hardware: We ran this cell through charge and discharge on the FreeLace Pro platform. The BMS accepted the new pack cleanly, balanced the cell, and reported accurate charge state through the neckband's indicator LEDs.
- First-cycle charging on the FreeLace Pro: After fitting, charge via the USB-C port on the neckband until the LED turns solid white. The earbud's touch controls and magnetic connection function will not re-initialise correctly until the cell completes that first full charge cycle.
Why the FreeLace Pro cuts out mid-call on a new or aged battery
The FreeLace Pro draws from a single 150mAh cell that simultaneously powers the audio driver, Bluetooth radio, and microphone circuit. Under a voice call, combined draw spikes above idle audio load. If the cell voltage sags below the BMS cutoff threshold — typically around 3.0V under load — the unit shuts off to protect the cell, even if the charge indicator showed partial capacity. A fresh cell handles this load without sag once it has completed two to three full charge cycles.
Earbud shows solid charge light but cuts off after a few seconds of use
A replacement cell shipped at storage voltage — usually 3.6V to 3.7V — can report a false full-charge state to the neckband's indicator circuit before the BMS has properly logged the cell's usable range. The unit then hits the low-voltage cutoff almost immediately under audio load. The fix is a single full charge from flat: drain the earbud completely, then charge uninterrupted until the LED goes solid white. After that cycle, the charge readout stabilises at 3.82V and the BMS tracks the cell accurately.