As electrification accelerates, power-hungry designs demand ever-denser power storage and charging solutions. Yet system-level challenges—such as thermal management, electromagnetic compatibility (EMC), and mechanical constraints—continue to define their practical limitations.
As part of the Future of Electrification 2025 conference, Chris Botting, Research Engineering Manager at Delta-Q Technologies, presented the session "Maximizing On-Board Charger Power Density," where he explored these challenges through the lens of power electronics and thermal management.
For OEMs striving to optimize charger performance without compromising on reliability or cost-efficiency, Botting’s insights provide a valuable guideline.
Top Three Takeaways
Rather than presenting a single solution, Botting’s discussion highlighted the tradeoffs inherent to power density. Three areas, in particular, emerge as critical considerations.
1. Power Electronics: Limitations of GaN/SiC
Gallium-nitride and silicon-carbide (GaN/SiC) semiconductors have introduced new possibilities in power electronics. Outstanding claims in consumer USB chargers suggest that significant size reductions—and therefore, greater power density—are easily achievable.
As Botting pointed out, the reality is more nuanced, with industrial applications facing constraints such as:
- Increased heat generation and reliability issues
- Shorter component lifespan
- Higher costs when scaled to industrial applications
These challenges are only the beginning. Electromagnetic compatibility (EMC), safety and regulatory standards, design for manufacturing principles, and many more tradeoffs exist when implementing power-denser electronics.
2. Advanced Cooling: A Challenge in Industrial Applications
Thermal management remains among the greatest constraints on power density in industrial chargers. Botting stressed three primary challenges related to cooling in high-power designs:
- Sealed enclosure – Most industrial chargers carry IP6/7 ratings, preventing the use of traditional air-cooling. Removing heat relies on conduction.
- Electrically live components – Many internal components cannot be directly connected to the case for cooling and require proper electrical isolation.
- Heatsink efficiency – Even after conduction extracts heat, it must be dissipated via convection. Poor heatsink design bottlenecks cooling performance, limiting power density in turn.
While liquid cooling solutions (such as cold plates) offer superior thermal performance, they also introduce varying costs and complexities. For example, liquid systems face the challenge of minimizing back pressure drop at high flow—all while ensuring efficient installation and non-leakage.
3. Mission Profile and Total Cost of Ownership
A well-engineered mechanical layout is critical to increasing power density, yet simply eliminating airspace is not always feasible. Per Botting, several factors must be carefully managed:
- Printed circuit board (PCB) airflow
- Insulating tapes and films
- Electromagnetic shielding
Since many of these components require manual assembly, OEMs must also weigh the tradeoff between power density gains and the labor cost of installation.
Final Takeaways: Incrementality is the Key
Botting concluded with a case study of an industrial EV charger that successfully doubled power density—not through a single technological breakthrough, but through incremental improvements in the above factors.
For OEMs seeking similar power-dense designs, Botting recommended a targeted design approach, focusing on cooling systems and mechanical design for high-impact, low-cost improvements.
With such a systematic methodology, greater power density is not only possible, but readily achievable.
To learn more, watch the video below, or reach out to a ZAPI GROUP expert to consult on your latest electrification project.