How To See An Electric Car (Part 1): Polestar 2
Polestar, Volvo’s electric performance sibling brand, today announced their first car that matters, the Polestar 2. There are numerous articles at the usual publications that give a good overview of the car generally, including Car and Driver, Slashgear, and Jalopnik. You can also watch a recording of the introduction on YouTube.
What I’d like to do here is use the Polestar 2 as an example of where electric vehicle design is at these days and help you see what you’re looking at when you encounter one.
The design starts with the battery. Rather than a pure, flat pancake design the battery modules are arranged to take advantage of any available volume. Here you can see, from left to right, battery modules under the front passengers, in the center tunnel, and under the rear seat. Voids exist for a lower rear seat footwell, allowing the rear passengers to sit more upright and reducing the wheelbase required for satisfactory rear leg room.
The battery, including mounting plates for thermal control, is then packaged within a protective aluminum and steel case.
The encased battery package attaches to the body shell as a stressed component. In other words, the battery doesn’t just hang below the body. It is essentially part of the body and, as such, resists bending to made the overall body more rigid. This, in turn, allows for better handling. As a small example, more damping can be used in the suspension without causing excessive body flex.
With the battery in place we can now consider the car’s overall packaging.
The underfloor battery tends to raise the overall height of the body by several inches. This is visually compensated for by the black trim along the bottom making the body appear, at casual glance, to end at the bottom on the painted surface. Larger diameter wheels help the car appear less elevated and allow for powerful, large diameter brakes to cope with the typically heavy weight associated with a large battery. Large 19 inch wheels are standard on the Polestar 2 with 20 inch wheels optional.
Volvo S60
The lack of a front engine allows the driver’s hip point to be brought forward closer to the front axle. Notice the difference between the Polestar 2 and Volvo S60, two otherwise similar sedans, with regards to the space between the front door’s forward cutline and the wheel opening. It is minimal on the Polestar, much larger on the Volvo. This allows for a roomier, more open cabin for the same wheelbase.
This is intended to be part of series. In Part 2 I plan to address aerodynamics, battery capacity, and range.
