It’s no secret that vehicle electrification is accelerating, and many smaller and mid-sized manufacturers are making the move to the electric vehicle (EV) space. From classic car conversions and low-volume automotive manufacturers to compact off-road vehicles and small -mid range construction equipment, these companies face a unique set of challenges, particularly when it comes to managing heat and temperature within their new electric platforms.
Often producing fewer than 1000 vehicles a year, these manufacturers play an important role in meeting growing demand for low-emission transport, especially in areas where mass-market EVs fall short. But with fewer resources, smaller teams, and unique technical constraints, these companies must approach thermal design with care.
In this blog, we will discuss how getting thermal design right from the start can reduce risk, speed up time to market, and improve vehicle reliability for end users.
Why Thermal Management Is So Important
Thermal control isn’t the flashiest part of an EV program, but it’s one of the most important elements. Electric drivetrains generate and depend on heat in very different ways compared to combustion engines. Batteries, inverters, motors, and even the cabin climate system all require thermal control.
Without well-planned heat management:
- Batteries can overheat or underperform.
- Range can drop sharply in cold weather.
- Cabin comfort suffers, especially in extreme conditions.
- Reliability and validation times take a hit.
Getting thermal management systems right from day one can make or break the success of an electric platform.
The Unique Challenge for Low-Volume OEMs
Smaller manufacturers often operate under tight space, budget, and time constraints. Many repurpose existing chassis or design vehicles that were never intended to house battery packs or cooling circuits. That makes packaging and layout a constant puzzle and requires engineers to find creative ways to keep temperatures under control without major structural changes.
Another issue faced is that of conflicting temperature needs:
· Batteries need to stay within a narrow temperature range (typically between 15–35°C) for safety and performance.
· Motors and inverters generate high heat that must be removed quickly to ensure reliable and efficient performance
· Passenger comfort demands efficient heating and air conditioning. Comfort for the occupant can be the difference of just a single degree, driving fine control and ability to respond to changing operational and environmental factors swiftly.
Balancing those demands with limited electrical and physical resources takes expertise and planning. And while major OEMs have teams of thermal specialists, many low-volume builders don’t. That can lead to gaps early in the process. Airflow may be overlooked, hot/cold cycles may not be simulated, or the thermal interaction of components may be underestimated. All of these may result in performance issues, longer validation periods, or costly redesigns.
Without a dedicated in-house thermal specialist, it can be difficult to stay fully up to speed with the latest advances in this area of engineering—or to understand how best to apply them to your specific platform. This can lead to those “unknown unknowns” that catch teams off guard: missing potential pitfalls, or overlooking proven technologies and solutions that could prevent them. The question is—do you have the right expertise in place to spot these challenges early and turn them into opportunities?
Designing for Success: Lessons from the Field
At Calatherm, we’ve seen firsthand how proactive thermal thinking accelerates EV development. Here are some proven approaches that work:
1. Start Early
Thermal planning shouldn’t wait until prototype testing. Build it into the concept and layout stages. Ask those early questions like:
· Where are heat-generating components located?
· Is there space for coolant flow or air ducts?
· Are sensitive components insulated or isolated?
· What are the peak environmental conditions expected?
2. Think Systems, Not Parts
Thermal behaviour is highly interconnected. A well-cooled motor may still lead to poor performance if the battery overheats. A comfortable cabin can drain energy if not properly integrated with the rest of the vehicle’s thermal loops. By thinking of whole systems, rather than individual parts, you can avoid unexpected interactions and energy losses.
3. Validate in Real World Conditions
Simulation is essential, but nothing replaces real-world testing under extreme conditions. Testing under heavy loads, hot and cold ambient temperatures, or stop-start operations reveals issues that models can miss.
4. Keep It Simple
Complex thermal systems can be hard to service and expensive to build. Simplicity improves reliability and maintenance, especially for fleets or low-volume production runs.
The Payoff: Reliability, Range, and Reputation
Well-engineered thermal systems deliver value at every stage:
- Faster validation and certification
- Extended battery life and efficiency
- Improved comfort and user experience
- Lower risk of warranty claims and customer issues
Thermal design isn’t just an engineering concern; it’s a business advantage. And ultimately, well-managed heat and temperature make the vehicle more competitive, more reliable, and more enjoyable to use.
The Road Ahead
Thermal management doesn’t have to be complex, but it must be deliberate. As EV production scales across niche and specialist markets, the winners will be those who integrate thermal strategy from day one.
At Calatherm, we help OEMs plan, design, and validate bespoke thermal systems for low- and mid-volume platforms. Our collaborative approach bridges the gap between concept and production—delivering solutions that are practical, scalable, and serviceable.
If you’re exploring or expanding your electric vehicle program, we’d love to discuss how we can support your next step. Get in touch today.