Battery System Engineer, 100% (m/w/d)

ABOUT THE COMPANY

Sphere Energy is a dynamic and technology-driven company, committed to developing solutions that revolutionize physical product development. We have successfully scaled from battery as a main technology focus, to the broader engineering world; with a mission to fundamentally change how engineering is done by leveraging the newest deep-tech models and unlocking the latent potential of internal company data. Backed by significant funding, and with teams across Germany and Switzerland, we are partnering with global and European industry leaders to become the category-defining AI Operating System for engineering companies.

ABOUT THE ROLE

We are looking for an experienced Battery Design Engineer to join our growing team in Grossaitingen and take ownership of designing and prototyping high-performance, small-scale battery systems. Working at the critical intersection of testing engineers, our AI/simulation team and the client, you will translate complex system requirements into physical prototypes for demanding, high-demanding applications. This includes leading end-to-end battery pack architecture, hands-on prototype assembly, and data-driven validation workflows. This role demands strong hardware engineering fundamentals, practical lab experience, and analytical curiosity. We are offering more than a job, it is an opportunity to help shape the next generation of battery engineering.

RESPONSIBILITIES

• Lead the end-to-end design and architecture of compact, high-demanding battery packs tailored for non-automotive applications such as robotics, eVTOLs, or other specialized industrial systems.

• Build, assemble, and iterate on small-scale battery pack prototypes hands-on in our lab, ensuring mechanical, electrical, and thermal reliability.

• Design and execute system-level testing and validation protocols to evaluate performance, safety, and durability under real-world operating conditions.

• Analyze test and operational battery data using Python to extract actionable insights, validate models, and drive continuous design improvements.

YOUR PROFILE

• Degree in Electrical Engineering, Mechanical Engineering, Materials Science, Energy Systems, or a related technical field with proven industry experience in battery pack design.

• Demonstrated track record in designing compact, high-performance battery packs for demanding applications (e.g., robotics, aerospace/eVTOL, or specialized mobility).

• Hands-on experience in building and assembling battery pack prototypes, including cell selection, mechanical integration, thermal management, and safety considerations.

• Solid background in system-level battery testing and validation workflows, with the ability to troubleshoot hardware and interpret complex test results.

• Strong data analytics skills, particularly in Python, for processing battery test data and collaborating effectively with AI and simulation engineers.

• Fluent in English; German language skills are strongly preferred.

BENEFITS

• A high-impact, hands-on engineering role with real responsibility and room for initiative

• The opportunity to drive leading technology solutions in real-world applications

• A collaborative and dynamic work environment that values vision and impact

• High impact by actively contributing to the company's growth

• Flexible working hours and hybrid work models