Feature: Thermal management


Figure 1: The Betterfrost solution moves away from bulk air heating to conductive, surface-specific heating, managed by a 48V power control module. Windshield ice is melted in under 60s


A new approach to windshield defrosting in EVs


By Derrick Redding, CEO, Betterfrost Technologies


D


rivers in cold climates know that the chore of defrosting windshields is a laborious seasonal reality. Time-saving hacks abound, from scrapers and defrost sprays to the ill-advised hair dryer. In the end, the traditional residual car engine heat and blower fans are the proven remedy, even


if that means waiting (and waiting!) for the heat to reach its ice- melting point. Now that we have firmly moved into the era of the electric


vehicle (EV), automotive engineers are facing a different challenge. It is no longer just about EV’s raw power or peak charging speed,


34 September 2026 www.electronicsworld.co.uk


but about its thermal management. As vehicles transition to 800V architectures and massive battery packs, the industry is confronting an uncomfortable reality: cold weather is a range killer. Data from the 2026 Yakeshi Winter Mega-Test in inner Mongolia (-25°C) and the Norwegian Automobile Federation Winter Test confirms that most EVs lose between 35% and 55% of their rated range in extreme cold. Tat means a 500km-range EV in summer may have a range retention of only 250-350km in winter. Tis is not a battery chemistry failure, but a thermal management crisis. When an EV wakes up at -20°C, the conventional positive temperature coefficient (PTC) cabin heater is an enormous energy drain, pulling a continuous 7-10kW just to defrost the windshield and warm the cold cabin air, in addition to warming seats and the steering wheel.


The problem with 1:1 heating Te legacy approach in automotive windshield heating has been to use the waste heat generated by the internal combustion engine. But, as passenger cars and commercial trucks transition to electric powertrains, this free heat byproduct disappears, leaving vehicles to draw energy from the main battery to defrost and defog. In the traditional approach, the -20°C standard defrost cycle can


consume ~ 2.8kWh of energy before the driver can even safely see the road and start driving – up to 20 minutes aſter starting the vehicle. It also can take 10 minutes for the cabin to reach cabin comfort at +15°C from a cold start. Tus, energy transfer chain is inherently inefficient as it passes


through five stages: 1. PTC heater: High power load converts electricity to thermal energy.


2. Coolant: Termal energy is moved via fluid through a hose network.


3. HVAC heat exchanger: Heat is transferred from the liquid coolant to the air.


4. Air: Te warmed air passes up from the bottom of the glass surface.


5. Glass: Heat is finally transferred from the air into the thermal mass of the windshield, to the ice or frost on the exterior of the car.


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44