Test Engineer - Battery Electronics

Joby Aviation•San Carlos, CA

2d•$104,400 - $183,500

About The Position

Joby Aviation is seeking a passionate, motivated and hands-on Senior Test Engineer on the Energy Storage and Distribution System (ESDS) Test Team to lead characterization, performance, environmental and reliability testing of the high-voltage electronics within the ESDS, including power distribution units, power conversion electronics (DC/DC converters), battery management system (BMS) hardware, contactors, fuses, current/voltage sensing circuits, and related PCBs. This role is a member of the Powertrain & Electronics Testing Team and leads the verification and validation testing activities for flight-critical HV electronics, with specific emphasis on electrical stress and abuse testing, HV insulation and isolation verification, electrical-thermal cycling, and Electromagnetic Effects testing (such as EMI/EMC, HIRF, and lightning-induced transients).

Requirements

B.S. in Electrical Engineering or relevant discipline with 5+ years of work experience in a relevant industry performing Test Engineering activities on high-voltage electronics or battery systems, OR Advanced degsree and 3+ years of experience
Experience testing high-voltage, high-power electronics (such as power distribution units, DC/DC converters, contactors, fuses, and protection circuits) in electric vehicle, aerospace, or similar applications
Practical experience with HV electrical test methods including dielectric withstand (hipot), insulation resistance, isolation monitoring, and high-current/transient measurements
Practical experience using lab equipment such as oscilloscopes (including HV differential probes and current probes), data acquisition systems, power analyzers, programmable power supplies and electronic loads, and battery cyclers/emulators
Experience with environmental stress testing of electronics including thermal and humidity cycling, vibration, and electromagnetic interference
Domain knowledge of battery monitoring techniques, cell and pack failure modes and mitigation, and high voltage safety
Strong data handling, processing, and presentation skills, with excellent problem-solving techniques and analytical ability
Positive attitude and willingness to work individually and as part of a team; maintains a clean workspace and inventory of tools and equipment
Be agile and adapt to evolving requirements and changes in direction

Nice To Haves

Experience testing or verifying Battery Management System hardware, including functional verification of protection and measurement circuits
Experience testing airborne electronic hardware to DO-160, DO-311A, SAE, MIL-810 (or similar standards) environmental tests; prior DO-160 training is a plus
Knowledge of Electromagnetic Compatibility (EMC) and Electromagnetic Interference (EMI) testing, including HIRF and lightning-induced transient susceptibility
Experience with high voltage Lithium-ion battery systems and battery pack cycle test equipment
Experience with instrumentation (e.g. contactors, current/voltage sensors, thermocouples, accelerometers, strain gauges) and data acquisition
Practical knowledge of root cause analysis (nondestructive) of electronics failure best practices
Experience with MATLAB/Python for post-processing of data from equipment under test and external instrumentation
Experience with LabView for data acquisition and test automation (invoking desired equipment functions in different conditions)
Experience with the aircraft FAA certification process
Strong physics and/or material properties background is a plus
M.S. in Electrical Engineering is a plus

Responsibilities

Test preparation includes: Test engineering: Identify test objective(s), collaborate with electrical design engineers and system engineers to devise test matrices, instrumentation and measurement needs (voltage/current sensing, isolation monitoring, high-speed transient capture), and outline detailed test procedures such that results are repeatable and consistent
Test article: Coordinate appropriate and configuration-controlled HV electronics test articles, power distribution and conversion hardware, BMS boards, contactors, fuses, special connectors, and PCBs, to meet test objective(s)
Test equipment: Work closely with Test Equipment Design Engineers to have custom HV test rigs, battery emulators/cyclers, and programmable load setups built, assembled, operated, and maintained; define electrical requirements and expectations of the test stand/test setup, including HV interlocks, isolation barriers, and grounding/bonding schemes
Lab integration: Aid in the integration and maintenance of various ESDS labs, including a complete aircraft representative battery lab and power distribution, power conversion, and BMS electronics labs, while strictly adhering to HV safety best practices, proper documentation, and safety awareness
Test execution includes: Perform electrical characterization, qualification, and reliability testing of ESDS HV electronics, including dielectric withstand (hipot), insulation resistance, contactor switching and fault-current interruption, bus transient/inrush characterization, and power/thermal cycling, plus environmental stress testing (thermal/humidity cycling, vibration and shock, accelerated life, and EMI/EMC, HIRF, and lightning effects)
Work closely with System Engineers on battery pack-level verification and validation, including electrical acceptance tests on aircraft representative packs with Safety-of-Flight documentation, evaluation of BMS functional behavior and battery algorithms (SoC, SoE, etc.), and validation of protection functions
Analyze electrical test data (waveforms, power quality, thermal-electrical performance) to generate reports that give design teams quantifiable feedback for design optimization and certification compliance; perform root cause investigation and failure analysis of HV electronics, documenting findings for corrective action
Coordinate and lead test kickoff, test readiness, and data review meetings; work with the Test Program Manager to plan work, schedule test resources, report progress, and ensure tests are properly documented and closed out
Work closely with Design Engineers, System Engineers, DERs, and Certification Engineers to verify ESDS HV electronics meet design requirements; author Qualification Test Plans and Procedures (QTP) and balance iterative R&D testing with formal FAA witnessed Qualification testing
Aid in the incremental automation of pack, and BMS, functional electrical test setups while applying deep knowledge of HV safety threats, lockout/tagout, and prevention best practices