Polestar is developing a new structural battery pack that’s built directly into the vehicle’s chassis. A patent application filed with the European Patent Office describes a design where the battery is engineered to form an integral part of the chassis itself. While Tesla has gained attention for using structural battery packs to improve rigidity and reduce weight, Polestar’s approach pushes the concept even further by embedding the battery as a core element of the vehicle’s frame.
The Industry Standard: Structural Battery Packs
With Chinese EV maker Nio being one of the rare exceptions with its separate battery packs that can be swapped for a fresh one in five minutes, most automakers have adopted structural battery packs. These are strong battery packs with stiff housings that are securely bolted to the vehicle, forming part of its structure and improving the car’s rigidity. It also saves weight because the battery acts as a structural member, not just dead weight.
Polestar’s Fully Integrated Approach
Polestar takes the structural battery concept a step further by integrating it directly into the vehicle’s frame and chassis, rather than treating it as a bolted- or welded-on component. The battery housing is built into the frame rails and connects seamlessly with the front and rear body extrusions, creating a rigid, enclosed structure designed for maximum torsional stiffness. Even the coolant pipe assembly is integrated into this space, emphasizing Polestar’s commitment to a fully unified design.
Why It Matters: The Benefits of a Fully Integrated Battery
Building the battery pack directly into the vehicle’s structure brings a range of key advantages:
- Lower overall weight
- Increased strength and torsional rigidity
- Enhanced safety and protection for the battery
- Better crash impact resistance
- More space for battery cells
- Longer driving range as a result of all the above
Polestar hopes to popularize this type of EV construction, where the battery pack is the main structural component of the vehicle body. The fully integrated design not only reduces weight but also allows for larger, more energy-dense packs that can extend driving range without compromising safety or performance.
