The next level of aviation is here. The race to commercialize electric vertical takeoff and landing (eVTOL) aircraft is accelerating. Companies like Joby Aviation, Archer, and Wisk are pushing toward FAA certification and real-world deployment. With that comes one of the most demanding engineering challenges in the industry: keeping batteries cool enough to charge quickly and remain commercially viable.
The heart of this challenge is heat — lots of it. And Delta T Systems knows this well. For over 3 decades, we’ve been solving thermal management problems in some of the most demanding industries. Now, that same engineering expertise is powering the next frontier of aviation.
Why eVTOL Battery Heat Is a Unique Engineering Problem
eVTOL (or vertiport) batteries are designed to charge extremely fast, often in 5 to 10 minutes, to support repeated quick trips where the battery is mostly depleted between flights. Remember, these aircraft need fast turnarounds to unload one set of passengers and load the next at a rapid charge rate. This means eVTOL batteries need to handle both charging and thermal management of the battery system simultaneously.
That kind of charge rate generates intense thermal loads that standard cooling systems simply weren’t designed to handle. Battery packs in eVTOL aircraft generate significant heat spikes during the most energy-intensive phases of operation, particularly takeoff and landing, and power demand varies widely across takeoff and landing, adding to the complexity of thermal management.
One major study to comprehensively evaluate battery thermal management systems specifically designed for eVTOL flight conditions. The research published in Applied Thermal Engineering (Wu et al., 2024) found that effective passive cooling systems must maintain battery temperatures no higher than 101.2°F (38.46°C), with temperature differentials across the battery pack kept within 6.9°F (3.85°C) to preserve both safety and cell performance. The optimal operating temperature for conventional lithium-ion batteries falls between 68°F and 104°F (20°C and 40°C), with temperature differences between cells not to exceed 9°F (5°C).
That is an extremely narrow window to maintain across hundreds of charge-discharge cycles per day. Overheated cells lead to permanently degraded performance and reduced battery life. In extreme cases, uneven heat distribution can trigger thermal runaway, a cascading failure where cells ignite in sequence. This is where precise cooling is mandatory.
The Consequences of Getting eVTOL Battery Cooling Wrong
Battery performance in eVTOL applications isn’t just about avoiding catastrophic failure — it’s about protecting cell integrity and operational lifespan across thousands of cycles. Poor thermal management increases the degradation of the entire system.
eVTOLs also require higher efficiency from their battery thermal management systems than EVs do, meaning greater emphasis on size and weight constraints, which creates an inherent tension. More cooling capacity typically means more weight, and in aviation, extra weight is never good. The most practical solution to that tension is offloading thermal management to the ground.
Industrial Temperature Control in Ground-Side Cooling
For eVTOL manufacturers and vertiport operators, the solution to rapid, safe charging isn’t found onboard the aircraft alone. It’s in the ground infrastructure.
Offloading thermal management to a ground-side cooling system means less thermal equipment weight on the aircraft while enabling more precise, consistent temperature control than an onboard-only system could achieve. The ground station can apply significantly more cooling capacity than the aircraft could ever carry.
This is the kind of application where Delta T Systems’ industrial chillers have been built to perform. We’ve created custom chillers that cool the batteries of the eVTOL while they are charged on the landing pad. The system manages the intense heat loads generated by rapid charging, maintaining battery temperatures within the precise window that research confirms is essential for cell safety and longevity.
What Precision Cooling Looks Like at the Vertiport
For a commercial vertiport cooling system, the requirements are demanding:
- Tight temperature control: Lithium-ion battery chemistry is sensitive. Fluid temperatures must stay within a narrow band to protect cell integrity and enable maximum charge rates without causing lithium plating.
- High heat rejection capacity: Fast charging produces substantial heat that must be removed quickly and consistently. A cooling system that can’t keep pace with the charge rate isn’t a stable cooling system.
- Reliability under continuous cycling: A busy vertiport may turn aircraft over dozens of times per hour. Cooling equipment must perform without interruption across every single cycle.
- Scalability: As eVTOL fleets grow, ground-side cooling infrastructure must grow with them. That requires systems that can be replicated, expanded, and customized to site-specific requirements.
A New Industry, Proven Expertise
eVTOL is a genuinely new frontier. But the thermal management principles that make it work aren’t new at all. As the eVTOL industry builds out the ground infrastructure required to make urban air mobility a reality, the companies leading the way are turning to proven industrial partners who understand what precision cooling actually requires at scale.
Delta T Systems designs custom cooling systems for companies that manufacture mobile battery racks for energy storage. We specialize in customer service and are dedicated to helping each customer have the optimal chiller system for their specific needs.