Battery Test & Diagnostics Engineer

Position Title: Battery Test & Diagnostics Engineer

Duration: Contract

Location: Banbury, Oxfordshire.

• Our Client is seeking a technically capable Battery Test & Diagnostics Engineer to support high-voltage battery and power-system commissioning, diagnostics, validation and engineering fault resolution.
• This hands-on role supports prototype and production build phases, with PEOL/EOL testing providing the environment for proactive engineering investigation rather than routine test execution alone.
• The engineer will independently isolate complex failures, test engineering hypotheses and drive corrective action across battery hardware, BMS, electrical interfaces and test systems.

Key Responsibilities:

• Diagnose HV battery pack, BMS and power-system faults covering contactors, pre-charge circuits, HVIL, insulation monitoring, voltage/current sensing, thermal management and control interfaces.
• Interpret electrical schematics, CAN/XCP logs, diagnostic codes, oscilloscope traces and DAQ measurements to isolate hardware, software, calibration, network or test-equipment faults.
• Own systematic fault investigations from symptom reproduction and hypothesis development through root cause confirmation, corrective action and verification of resolution.
• Apply structured RCA methods including 5 Whys, 8D and fault-tree analysis; investigate intermittent, repeatable and operating-condition-dependent failures.
• Develop and perform controlled fault-injection and abnormal-condition tests to verify BMS diagnostics, fault detection thresholds, protective actions, interlocks and recovery behaviour.
• Use approved risk assessments, authorised equipment and safe test methods for all HV and fault-injection activities.
• Execute and technically assess PEOL/EOL commissioning and performance tests; investigate failed results rather than simply repeat or reset test sequences.
• Distinguish genuine product failures from false failures, test-rig limitations, incorrect limits, communications faults and calibration issues.
• Analyse trends in test data, identify recurring defects and recommend improvements to test coverage, test limits, diagnostic methods and production robustness.
• Develop or adapt diagnostic routines, test scripts, data acquisition and engineering test procedures to support investigation and validation.
• Work with battery design, BMS software, validation and manufacturing engineering teams to agree engineering fixes and verify their effectiveness.
• Produce clear test evidence, technical investigation reports, root-cause findings and practical recommendations; proactively escalate safety or delivery risks.

Key Requirements:

• Strong hands-on engineering experience with HV battery packs, battery management systems or closely related EV energy-storage and power systems.
• Proven ability to independently fault-find complex electrical, electronic and system-level issues and deliver evidence-based root cause analysis.
• Sound understanding of battery pack architecture, contactors, pre-charge, HVIL, insulation monitoring, sensors and BMS fault/protection strategies.
• Practical experience in fault injection, diagnostic validation, abnormal-condition testing or equivalent controlled fault simulation.
• Competence interpreting wiring diagrams, electrical schematics, system architectures, CAN signals and diagnostic data.
• Experience using oscilloscopes, multimeters, DAQ systems and CAN/XCP tools such as Vector CANoe, CANalyzer or CANape.
• Ability to analyse data, develop diagnostic hypotheses, challenge test outcomes and independently drive technical problems to closure.
• Formal HV training, safe-isolation competence and disciplined adherence to HV safety procedures and risk controls.
• Degree, HND or equivalent relevant experience in Electrical, Electronic, Automotive, Mechatronics or Systems Engineering.

Tools & Knowledge (Desirable):

• Lithium-ion battery module/pack validation, thermal management and BMS calibration experience.
• PEOL/EOL test development and engineering support in prototype, low-volume or production EV environments.
• Test scripting and automation using Python, MATLAB, LabVIEW or similar tools.
• Knowledge of DFMEA, DVP&R, fault coverage, diagnostic thresholds and software/hardware integration.

Candidate Profile:

• A proactive, technically inquisitive engineer who does not stop when an EOL test reports a failure.
• The successful candidate can explain why the system failed, safely reproduce and isolate the issue, establish the root cause and drive an effective engineering resolution.