EV battery management systems monitor battery state of charge and temperature, requiring high insulation, sealing, and anti-interference performance, protecting internal circuit boards and sensors. Traditional assembly methods have poor sealing and insulation, leading to circuit short circuits and inaccurate monitoring. DaokeDao plastic laser welding provides a reliable solution for PC/ABS and PA BMS housings, achieving IP67 hermetic sealing, blocking moisture and dust, and insulation resistance ≥10¹²Ω. The non-contact process generates no vibration or debris, protecting internal electronics, and the heat-affected zone ≤0.2mm, avoiding component damage. The equipment supports complex housing designs with multiple interfaces, automated production, cycle time 8-11 seconds per unit, full parameter traceability, complying with IATF 16949 and IEC 62133 standards, helping EV manufacturers improve battery management accuracy and safety.