HV Battery Systems Engineer

Job Title: HV Battery Systems Engineer

Location: Banbury, UK

Project duration: 12 months with possible extension

Salary: GBP45k/year (Slightly negotiable for strong candidates)

Hybrid work model: 5 days/week from client location

Job Summary:

As a Systems Engineer within the Powertrain Systems Engineering group, you will drive the Battery Management System (BMS), firmware control engineering, and overall hardware integration for our active SAE Level 5 autonomous EV platform. You will play a pivotal role in optimizing BMS algorithms, system behaviors, and operational reliability for our deployed energy storage systems. Collaborating with a cross-functional team of exceptional engineers, you will break down complex BMS, firmware, wire harness, and system integration challenges into actionable solutions. Additionally, you will drive firmware release planning, investigate the root causes of faults, resolve hardware quality issues, and implement updates that extend our operational domains directly into our current production vehicle.

Responsibilities:

● Manage, troubleshoot, and refine the electrical architectures and control strategies for our current Battery Management Systems (BMS).

● Actively resolve HV battery system-level challenges, managing wire harness updates, addressing manufacturing or hardware quality issues, and ensuring seamless vehicle-level system integration.

● Take an active role in firmware release and hotfix planning, liaising with cross-functional software and controls teams to define, secure, and deploy critical updates to the production fleet.

● Integrate and validate new firmware updates to extend our vehicle operational domains, enabling enhanced system performance and safety across challenging environmental and operational conditions.

● Lead technical engagements with external suppliers to support, optimize, and improve existing BMS hardware, firmware, and associated HV battery designs.

● Maintain and update system integration documentation, DFMEA, and Fault Tree Analysis (FTA) with a strong focus on BMS fault diagnostics, contactor control, and charge/discharge handling strategies.

● Plan, lead, and execute BMS and HV battery system testing (including HIL/SIL), translating complex telemetry and test data into actionable insights to inform firmware updates and continuous improvements.

● Conduct comprehensive reviews for BMS subsystem component updates, algorithm modifications, and engineering changes with internal teams and external partners.

● Monitor active field performance by analyzing BMS telemetry and vehicle logs, performing deep root-cause analyses on control or hardware faults, validating firmware hotfixes, and driving field issues to complete resolution.

Qualifications:

● BS or MS in Electrical Engineering, Computer Engineering, or a related technical field.

● 3–5+ years of experience engineering Battery Management Systems (BMS) and EV HV battery systems, with a proven track record of sustaining products in the market and successfully solving complex field issues.

● Deep technical knowledge of BMS control algorithms, including State of Charge (SOC), State of Health (SOH), cell balancing, and charge/discharge boundary management.

● Proficiency with automotive communication protocols (CAN, LIN, FlexRay, Ethernet, SPI, I2C) essential for BMS integration and vehicle-level communication.

● Demonstrated experience and stringent safety practices working with high-voltage systems (up to 500VDC).

● Hands-on experience with simulation tools (MATLAB/Simulink, LTspice) and programming languages (Python, C, C++) used in BMS algorithm development, validation, and data analysis.

● Genuine passion for electric, autonomous mobility. Must be a highly collaborative team player with excellent communication skills, capable of thriving in a fast-paced production environment.

Bonus Qualifications:

● Solid understanding of global testing and safety standards (SAE, MIL, UN, UL, GB/T, GTR).

● Practical experience with HV and LV PCB design and debugging.

● Strong grasp of EMI/EMC principles and mitigation strategies.

● Hands-on ability to effectively utilize lab equipment, including high-voltage DC power supplies, programmable loads, digital oscilloscopes, and impedance analyzers.