Senior Battery Applications Engineer (Modelling) in London

Are you passionate about fighting climate change? Do you want to work on creating a world where everyone can breathe clean air? Do you want to have an opportunity to shape a growing company?

At Breathe, we believe an electrified future is key to achieving this, which is why we are building battery technology to help brands do more with the power they have. Our physics-based battery management software helps some of the world's largest and most iconic automotive and consumer electronics brands deliver products with faster charging, longer life and zero compromise on safety. Put simply, we make batteries better.

You will join a talented and cohesive team who everyday go to work to do more with the power we have. You will have the opportunity to have a big say in how the company is run and where we are going. You will become an agent of change and help us push the industry forward by helping make the complex simple and in return you have an opportunity to grow your career with us as we scale.

We offer flexible/hybrid working to try to accommodate your needs. We believe in keeping energy levels high and we have a constant supply of office snacks to help you with that. We offer share options, an ethical pension scheme and we know downtime is key to keeping the mind sharp, so we offer 34 days holiday per annum inclusive of Bank Holidays that we want you to take.

As well as the ability to learn from and with a room full of experts working at the cutting edge of the industry, we will provide the support and training to develop your skills, be that via courses, conferences or other learning opportunities/materials.

This role sits right at the intersection of our modelling capability and our customer relationships. As battery technology becomes more complex, our customers need someone who not only understands our software and models deeply, but can translate that understanding into clear, evidence-based recommendations that shape their product decisions.

Your day to day:

• Serve as the primary technical interface for a portfolio of customers, translating our modelling and software outputs into actionable guidance for their engineering and product teams.
• Develop a deep working knowledge of our battery models — enough to explain model outputs, uncertainty bounds, and limitations to sophisticated customer audiences.
• Lead customer campaigns end-to-end: designing test protocols, interpreting data against model predictions, and communicating results through high-quality technical presentations.
• Identify mismatches between customer expectations and model outputs early, working with our internal modelling and software teams to resolve them.
• Own the technical narrative in customer reviews and milestone meetings, including with senior engineering and product stakeholders at OEM and Tier 1 level.
• Collaborate with the embedded and modelling teams to feed customer insights back into product development, improving how our software performs across real-world use cases.
• Create and maintain customer-facing technical documentation, application notes, and integration guides that clearly explain complex model behaviour.
• Build and continuously improve workflows for customer onboarding, calibration, and performance reporting to support our growth.

Your background:

• Relevant industry or research experience in battery engineering, electrochemical modelling, or a closely related field.
• A solid understanding of battery physics and degradation mechanisms — enough to discuss model assumptions and interpret outputs critically, not just report them.
• Experience working with battery models (physics-based, empirical, or data-driven) in an engineering or research context — Python and MATLAB/Simulink experience is a strong plus.
• A demonstrated ability to communicate complex technical content clearly to varied audiences, including customer engineering teams and non-specialist stakeholders.
• Experience in client-facing or applications engineering roles, with a track record of owning customer technical relationships.
• Comfortable working across disciplines — able to hold a technical conversation with a modelling engineer in the morning and present findings to a customer programme manager in the afternoon.
• A proactive, kind and conscientious team player.

We want to add the best talent to our incredible team, and we want to find you tomorrow. We will do our best to process your application as quickly as possible and come back to you within 2 weeks as we appreciate communication is key.

At Breathe, we believe that having diverse perspectives within our team is an essential part of innovating quickly, thinking from first principles, and expanding our expertise. Ultimately, enabling us to deliver better products to our customers.

We aim to attract, nurture, and retain diverse individuals. Because that’s how we do our best work. And because that’s the kind of world we want to live in. We welcome and encourage applications from all qualified candidates and are happy to provide the accommodations you need within our recruitment process to enable you to demonstrate your skills. Just let us know what you need.

So, what are you waiting for? Come join us!