Power Electronics and Motor Test Engineer

SR2; Reading; On-site; GBP 90,000 - 125,000; Full time

Benefits offered by this job

Founding-team equity

On-site role in Reading

Job summary

SR2 seeks a Senior Test Engineer to build and own the test capability for electric propulsion motors and power electronics, shaping the measurement strategy and setting acceptance criteria.

You will establish a dedicated lab, design rigs, run performance and life testing, and drive data‑driven decisions with the design and hardware teams in a UK defence environment.

Qualifications

• Hands-on electrical measurement of efficiency, losses and thermal behaviour using oscilloscopes, current probes and power measurement equipment.
• Experience building test rigs, fixtures and instrumentation.
• Test automation and data acquisition in Python, LabVIEW or similar, with well-documented datasets.
• Knowledge of measurement uncertainty, calibration and traceability.
• Ability to work safely with high voltage, high current and rotating machinery.

Responsibilities

• Characterise motor controllers across full operating envelope including efficiency, thermal behaviour, derating, losses and control loop response.
• Run like-for-like benchmarking against competitor products and maintain the comparison used by engineering and commercial teams.
• Design and build test rigs, fixtures and instrumentation with workshop, hardware and firmware teams.
• Plan and set up the test facility, including layout, dyno cells, and environmental and life test capability as the programme grows.
• Manage test data to keep results comparable across products and over time.
• Define acceptance criteria for controllers and motors and own qualification evidence for production testing.

Job description

Senior Test Engineer – Electric Propulsion (Motors & Power Electronics)

Defence / Unmanned Aircraft | On-site, Reading | Competitive salary + founding-team equity

The Company

My client is a fast-growing UK defence technology company that designs and manufactures electric propulsion systems (brushless motors, power electronics, firmware and control algorithms) primarily for unmanned aircraft.

Unlike most of the industry, they don't subcontract. Motor production, electronics assembly and test are all done in-house at their UK site, and they own their own PCB fabrication facility in Europe, so they control every board from layout to assembly. Most propulsion hardware in this market is made in China, and defence customers increasingly won't accept that. This vertically integrated model positions the company to fill that gap.

They are now moving from prototype to volume production. The engineering team is small but growing quickly, key leadership is in place, and they are hiring exceptional engineers to build out the team.

The Role

This is a founding test role, reporting to the Head of Engineering. You will own performance testing of the company's motor controllers and motors: designing the tests, building the equipment to run them, and producing the data the design team makes decisions from.

There is no existing test plan and no existing lab. You will decide what is worth measuring, work out how to measure it properly, and build the facility to do it. You start as a team of one, and the role grows into leading the test function and hiring into it as the product range expands.

The work has two strands:

• Development testing alongside the design team, to establish how the company's products and competitors' products actually perform. This is the current focus.
• Independent verification, confirming that shipped products meet their stated specifications independently of the people who designed them. This becomes more important as designs mature, and you will build that capability as the need arises.

Your first project is to characterise the in-house motor controller against competitor products on the same rig and under the same conditions. That comparison will show where the product stands, provide the evidence for setting future requirements, and become the benchmark for every product that follows. The programme then extends to motor performance and life testing across real in-service conditions.

You don't need deep experience in both power electronics and motor testing on day one. Strength in one and a genuine interest in learning the other is a good starting point.

Key Responsibilities

• Characterise motor controllers across the full operating envelope, including efficiency mapping, thermal behaviour and derating, switching and conduction losses, ripple, and control loop response, and explain what the results mean for the design.
• Run like-for-like benchmarking against competitor products, and maintain the comparison used by both engineering and commercial teams.
• Turn benchmark data into performance requirements for next‑generation designs, and track products against them.
• Specify, source, commission and calibrate test equipment (power analysers, electronic loads and supplies, oscilloscopes, current probes, thermal imaging, DAQ, and a dynamometer), including building the business case for capital spend.
• Design and build test rigs, fixtures and instrumentation with the workshop, hardware and firmware teams.
• Extend testing to motors: dyno characterisation, torque/speed/efficiency mapping, back‑EMF and parameter measurement, thermal profiling and life testing.
• Plan and set up the test facility, including layout, dyno cells, and environmental and life test capability as the programme grows.
• Manage test data so results stay comparable across products and over time, and remain usable by others.
• Maintain measurement integrity through uncertainty budgets, calibration schedules and traceability.
• Define acceptance criteria for controllers and motors with the hardware, electromagnetics and firmware teams, and own the criteria and qualification evidence used in production testing.
• Run qualification and environmental campaigns (vibration, thermal cycling, humidity, shock), in-house or via external test houses.
• Act as the competent person for health and safety in the test facility, covering HV/high‑current working, rotating machinery guarding, risk assessments and safe systems of work.
• Recruit and train future members of the test team.

What They're Looking For

Essential

• 8–10 years in test, development or characterisation of power electronics, electric drives or electric motors, with genuine input into what was tested and why.
• Hands‑on electrical measurement of efficiency, losses and thermal behaviour using oscilloscopes, current probes and power measurement equipment.
• Experience testing hardware across a range of operating conditions and clearly communicating design implications.
• Experience building your own test rigs, fixtures and instrumentation.
• Test automation and data acquisition in Python, LabVIEW or similar, with well‑documented, reusable datasets.
• Sound understanding of measurement uncertainty, calibration and traceability, and the judgement to tell a real result from a setup artefact.
• Safe, competent working with high voltage, high current and rotating machinery, and willingness to hold competent‑person responsibility.
• Full right to work in the UK.

Desirable

• Full‑envelope characterisation of inverters, motor drives or converters, including high dV/dt probing and its pitfalls.
• Motor testing experience: dyno setup, torque/speed measurement, thermal instrumentation, endurance testing.
• Setting up a test lab or dyno cell from scratch.
• Motor development or electromagnetic design knowledge.
• Competitor benchmarking or teardown experience.
• Environmental and life testing, including reliability statistics.
• Familiarity with aerospace/defence qualification standards (MIL-STD-461, MIL-STD-810, DEF STAN 59-411).
• Degree in Electrical, Electronic or Mechanical Engineering, or Physics.

You’ll Thrive Here If You…

• Want to build a test capability from an empty room and grow it into a function.
• Enjoy building rigs as much as measuring with them, and are equally comfortable making the case for major capital equipment.
• Give straight answers about results, even when they're not what the design team hoped for.
• Can work with incomplete information, decide, test quickly and change direction without losing rigour.

Package

Competitive salary based on experience, plus meaningful founding‑team equity. This is a fully on‑site role.