A heatable car seat belt can reduce the energy consumption of electric vehicles (EVs) by reducing the use of climate systems. For instance, the seatbelt developed by ZF enables a longer range for EVs.
The range of electric vehicles depends on several factors, including the energy consumption of the vehicle. This obviously includes the consumption of the built-in electric motor(s), but also the use of other electric systems. An example is the climate control system present in cars.
Declining range
EV drivers notice in the cold winter months that their car's range decreases. This has several causes. For instance, batteries in EVs work optimally between 20 and 40 degrees Celsius, while temperatures are often a lot lower in the winter months. Their capacity is therefore limited, which can reduce the range of fully electric vehicles by up to 30 per cent.
However, heating in electric vehicles also plays a major role. In a traditional internal combustion engine, heating uses residual heat from the engine. An electric motor, however, does not generate this heat. An EV must therefore rely entirely on the energy stored in its battery to heat the interior.
Seat belt with electric heating elements
The heatable seatbelt developed by ZF could be the answer. This belt uses technology familiar from heated steering wheels and seat heaters. The belt incorporates electric heating elements, similar to an electric blanket. The heat given off by these elements in turn warms the occupants of a vehicle.
ZF aims to use the heatable seatbelt to warm occupants all around. This is possible by combining the seatbelt with seat heating. Here, the seatbelt heats the upper body and waist of occupants, while the seat heater heats the lower body.
Up to 15% more range
The impact on vehicle range is significant, according to ZF. For instance, the organisation expects the method to increase range by up to 15%. ZF also expects the system to provide a high level of comfort for occupants.
At first glance, heatable seatbelts are barely distinguishable from traditional counterparts. Heat conductors in the form of small wires are directly woven into the seatbelt. The contact elements for the electric heating circuits are positioned so that they do not interfere with the use of the seatbelt or belt tensioner.
No difference in safety
“For passengers, there is no difference in how it works compared to a conventional seatbelt,” explains Martina Rausch, who is responsible at ZF for new developments relating to seatbelts. “And, of course, in terms of crash performance, the heated seatbelt is in no way inferior to its conventional counterparts.”
Installation hardly deviates
ZF points out that the installation of heatable seatbelts hardly differs from the installation of conventional seatbelts. This is important for car manufacturers, which can therefore use the heated seatbelts more easily in series production. Also, the thickness of the seat belt is unchanged, which simplifies integration of the belt into vehicles. Many other seatbelts based on other technologies are actually thicker.
A key benefit of heatable seatbelts is also the speed at which they heat. ZF reports that as soon as the vehicle moves, the belts heat up. The closer the seatbelt is to the human body, the more effective the heating is. Taking off a winter coat can therefore speed up the process.
It is unknown if and which car manufacturers plan to integrate ZF's heatable seat belt into their EVs.
Author: Wouter Hoeffnagel
Photo: geralt via Pixabay
