Three-point seatbelts have come a long way since Volvo gave away the patent for free many decades ago. Some automakers are cramming airbags inside, but ZF has a different idea. Behold the Heat Belt, which as the name implies, takes the shape of a heated seatbelt serving as a warm hug. It's primarily intended for EVs to boost efficiency during cold weather. The thinking is the car will be using less battery juice to warm up the whole cabin.
While this may seem like a gimmick, the same thing was said about heated steering wheels back in the day. ZF has crunched the numbers and estimates an EV's range in low temperatures can increase by as much as 15 percent. The built-in heating conductors are embedded into the seatbelt to provide a uniform feeling of warmth while minimally increasing the thickness of the webbing.
ZF heat belt
Using about 70 watts of power, the seatbelts can be heated at up to 40 degrees Celsius (104 degrees Fahrenheit). ZF says its Heat Belt behaves like a regular seatbelt, meaning a car would not have to go through any modifications to accommodate them. The heating conductors are woven into the seatbelt structure and the location for the contact elements for the electrical heating circuits was chosen to not interfere with belt operation or retraction. Consequently, the standard belt retractors still work and the level of safety remains identical.
It should be mentioned a heated seatbelt is not an absolute premiere. In late 2018, Ford filed a patent with the USPTO, publishing a 31-page document detailing how the tech worked. Several variations on the concept with different designs were illustrated, but the idea was largely the same. About a year later, Mercedes introduced the GLE-based Experimental Safety Vehicle (ESF) and that one too had heated seatbelts.
It's still unclear whether automakers intend to implement this tech, but if there are real efficiency benefits, expect to see heated seatbelts in luxury EVs at some point.
