Thermal management for safe and efficient fast-charging of battery electric vehicles on the road

The interest in battery electric vehicles (BEV) is increasing. Yet, a continuous challenge is the availability of fast-charging stations while being on the road. In order to reduce charging time, the charging power needs to go up. As a result of this, the heat will rise significantly. To efficiently dissipate the heat and enable fast charging, controlled thermal management with liquid cooling is needed.

Most of the time, water and electronics do not mix, but increasing power output and circuit density in electronic systems has required more modern and effective ways of dissipating heat.

Today, there are mainly two challenges when it comes to the ability of fast charging Electric Vehicles (EVs). First, the availability of charging stations on the road. Mostly, EV’s are being charged at home or work, but whenever outside those areas, it is much harder to find a fast-charging station. The second challenge is the charging speed.

A typical 22 kW AC charger provides enough charge in 120 minutes to provide an additional 200 km of vehicle range (per article in Automotive Power). To reduce the 200 km range charge time to only 16 minutes, a 150 kW DC charging station is required. At this level of power, and to avoid overheating, an effective and improved thermal management is needed as the temperature can increase to more than 270°C during a 10-minute fast charge, according to a report from the U.S. Department of Energy.

Liquid cooling reduces charging time

Traditionally, air cooling has been the preferred solution, but with the fast-moving development, liquid cooling has been shown to be the most effective as air cooling systems charges more slowly. The heat capacity of water is also 3,500 times more efficient than the same volume of air, and up to 10 times more effective at dissipating heat from the source. Furthermore, liquid cooling enables working with pre-filled systems, which will facilitate the maintenance, expedite any necessary replacements, authorize quick initial installation, and expedite upgrades.

Liquid cooling can be found in many application areas. Among those, thermal battery pack, vehicle inverter, vehicle e-motor charging cable and charging station power electronics.

Quick connect couplings a key component in liquid cooling systems

In a field where uptime and reliability are the keys to success, utilizing high-quality components is highly important. Just as overheating, leakage in an electronic system is a common worry in case of an accident. Using quick connect couplings, which is a key part in a liquid cooling system, designed for long-term reliability with high flow and low-pressure drop, minimizes these risks.

CEJN ultraFLOW, a series of fluid couplings with a flat-face design, guarantees no-spill, high flow, and low-pressure drop. Using a non-drip coupler like ultraFLOW, outlined for a clean connection and disconnection, will extend the hardware life and keep running costs low.

 

Written by:

Mats Ahnheim
Product Manager Fluids

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