Test Engineer - Battery Systems

Fleetzero is electrifying global maritime shipping with marine-grade lithium-iron-phosphate battery systems built for the harshest environments on the planet. Our Leviathan battery platform is in active ABS Product Design Assessment, with hardware on test rigs today and production hardware shipping in the near term. We are hiring a Senior Test Engineer to take full ownership of our battery test program: The rigs, the procedures, the automation, and the evidence packages that turn engineering work into class-approved, vessel-ready hardware.

This is a hands-on role for an engineer who is equally comfortable wrenching on a fixture at 6 AM, debugging a CAN trace at noon, and presenting a thermal propagation test report to an ABS surveyor at 4 PM. You will own our hardware-in-the-loop (HIL) infrastructure, our cell/module/system-level test cells, and the requirements-to-evidence traceability that holds the whole program together. You will work shoulder-to-shoulder with our hardware, firmware, and systems teams to design tests early, fail hardware fast, and produce documentation that is self-explanatory to a first-time reader.

If you have ever looked at a battery abuse test cell and thought “I could run this better,” this is your job. What you’ll do

• Own the test rigs. Take full responsibility for our existing cell, module, and pack-level test stations: cyclers, environmental chambers, abuse test enclosures, HV safety systems. Improve them. Document them. Make them auditable.
• Stand up our HIL program. Architect and build hardware-in-the-loop infrastructure to validate BMS firmware (CMU/PMU/SMU layered architecture) against simulated cell, contactor, and vessel-level fault conditions. Drive HIL coverage upstream into the firmware development cycle.
• Author the test program. Write test plans, procedures, and reports for characterization, verification, validation, and abuse testing: including thermal propagation, overcharge, over-discharge, external short circuit, vibration, IP ingress, and thermal cycling. Make every report stand on its own as ABS evidence.
• Run witness testing. Execute ABS and USCG witness tests on-site, including pre-test dry runs, surveyor walkthroughs, and post-test documentation packages.
• Build traceability. Tie every test case back to a requirement, every result back to a test case, and every certificate back to a result. Help us mature requirements-to-test traceability tooling across the engineering organization.
• Automate and instrument. Develop Python (or equivalent) automation for cycler control, DAQ, post-processing, and report generation. Eliminate manual data wrangling wherever it shows up.
• Diagnose failures. Lead root-cause investigation when hardware fails on the bench, in qualification, or in the field. Translate findings into design and process changes.
• Grow the function. Help shape Fleetzero’s test engineering culture as we scale from R&D into production. Mentor junior engineers and technicians as the team grows around you., * Experience supporting class society (ABS, DNV, Lloyd’s, BV) or regulatory (USCG, Coast Guard, FAA, NHTSA) witness testing.
• Familiarity with UL 1973, UL 9540A, IEC 62619, UN 38.3, or equivalent battery safety standards.
• Functional safety background (IEC 61508, ISO 26262, or marine equivalents).
• Experience building out a test lab from scratch: Fixturing, safety systems, fire suppression, ventilation, HV lockout-tagout.
• Marine, naval, or shipboard experience. Bonus points if you have ever stood a watch.

How we work

We are a small, dense engineering team in Houston. We test early, test often, and break hardware on purpose. We work in person because integration problems live in the gaps between disciplines, and the gaps close faster when you can walk over to the next bench. We document because the next person who reads our work might be a class surveyor, a customer’s chief engineer, or a future version of ourselves at 2 AM in a shipyard.

Our team includes mariners, fabricators, software engineers, sales people. We respect the trades and the textbooks equally.

• Degree in Electrical Engineering, Mechatronics, or related field, or equivalent hands-on experience. We care about what you can do, not where you sat for four years.
• 5+ years of test engineering experience in batteries, energy storage, EV powertrains, aerospace, or another safety-critical hardware domain.
• Direct, hands-on experience with battery cyclers (Arbin, Maccor, Bitrode, Chroma, or equivalent) at the cell, module, or pack level.
• HIL experience using NI, dSPACE, Speedgoat, or equivalent platforms, and a clear point of view on what makes a HIL test rig actually useful versus merely impressive.
• Comfortable working around high-voltage DC systems. You know what an arc flash boundary is and you respect it.
• Strong scripting and data analysis skills in Python (preferred), MATLAB, or LabVIEW, including comfort building test automation from the ground up.
• Working knowledge of CAN, RS-485, Modbus, and other industrial communication protocols.
• Clear technical writing. Your test reports do not require a phone call to interpret.