Defrosting Tech Saves EV Battery Energy

Betterfrost Technologies’ patented solution de-ices EV windows in seconds.

May 9, 2023

Kami Buchholz

A freeze-frame from a video loop compares windshield defrosting time with Betterfrost Technologies’ solution, on the left, to a traditional HVAC system. (Kami Buchholz)

Turning on the heater in most EVs can be a range-killing decision due to the power draw of the vehicle’s HVAC. But while cold feet reluctantly is a better option than not arriving at your destination due to a depleted battery, having a clear, ice- and fog-free windshield and windows is a must. That’s why Betterfrost Technologies is capturing the interest of vehicle development engineers.

Betterfrost Techologies’ Derrick Redding stands next to the company’s concept demonstrator on the exhibit floor at SAE’s WCX 2023. Betterfrost won the 2022 Global Automotive and Mobility Innovation Challenge award, sponsored by the Michigan Innovation Alliance and SAE International. (Kami Buchholz)

The Ontario, Canada-based startup company’s innovative windshield deicing technology doesn’t drain an EV’s battery energy. The product consumes “20 times less power than the current HVAC systems that perform defrost and defog on EVs,” Derrick Redding, CEO of Betterfrost Technologies, told SAE Media during the 2023 WCX event in Detroit.

Betterfrost’s solution begins with low-emissivity glass it sources from a supplier. “Low-e” windshield glass has a conductive transparent layer, typically silver or fluorine-doped tin oxide (FTO). A busbar serves as the power conduit for the defogging and defrosting. Betterfrost provides a microcontroller which runs proprietary control algorithms, Redding noted.

“Our system provides high-voltage power that’s pulsed in a way to control how far heat can propagate from the glass surface,” he explained. “This is very fine pulsed control, less than 0.1 mm/0.0039-in, because we don’t want the heat to escape into the environment as that’s just wasted.”

The company’s technology has undergone numerous cold chamber lab tests for windshield defrosting and defogging systems. According to Redding, Betterfrost’s technology typically takes 50 to 75 seconds to clear the glass for driving. This compares with 20 to 25 minutes for the same results by traditional HVAC systems, Redding said. Testing to FMVSS 103 specifications was conducted at Ontario Tech University’s ACE lab in addition to lab testing by Tier-1 suppliers and vehicle OEMs.

Conventional HVAC systems were designed to perform in ICE vehicles and benefit from engine heat once the thermostat has opened. By comparison, HVAC power in an EV typically is generated by the propulsion battery and requires six heat transfers. “And it’s not evenly distributed as the heat is blowing from the base of the windshield,” Redding noted. He said Betterfrost’s technology can extend the driving range of a passenger EV by 38 km (23.6 miles) on average – a 5.5 kWh reduction – during wintertime thermal conditions, he claimed.

Product development work by Betterfrost’s 10-person engineering team currently is focused on integrating the technology with EV high-voltage electronics and power electronics. “Automakers can use their current supply chain to do the power electronics,” Redding said. “We would provide the micro-controller or software on a chip that would go into the climate controller or body control module.”

The innovative technology is likely three years from passenger EV production application. The timeline may unfold faster for commercial vehicles which Redding considers “a big value proposition” because most commercial trucks are parked outside year-round. Another reason that commercial vehicles could be the first application is not as obvious.

“Ophthalmologists released a study last year that showed 25 percent of commercial truck drivers have ‘dry eye’—the natural rate is about 7 percent. That’s because they’re driving for hours in the wintertime with the defrost blowing very hard onto the eyes,” Redding said.