Tesla’s Battery Day was not just full of surprises. When you read between the slides, Tesla made a lot of product announcements, many of which are still awaiting their discovery. The one this article is about is Tesla’s new battery pack.
What most people didn’t realize is that Tesla is abandoning its famous battery skateboard design. For those who didn’t know, until now, Tesla’s vehicles were composed of the body and a flat battery “skateboard” on the bottom that, as Tesla would say, are married together in the factory. We even witnessed the ceremony in person. Originally, the skateboard design was developed because it provided a low center of gravity and strong safety benefits, as well as the ability to quickly swap battery packs instead of just Supercharging if Tesla went down that road.
As you know, that last part didn’t end up happening. Now Tesla has gone back to the drawing board to make something better. However, it wasn’t just out of Tesla’s habit of successfully reinventing the wheel. The company has gone back to the drawing board because its cream-of-the-crop 4680 battery cells required it. You see, in the past, battery cells weren’t dense enough, so Tesla needed all the room it could get in the floor. If Tesla was to still do that now, vehicles would have incredible range, but Tesla wouldn’t be able to make a lot of them.
Tesla had to solve a few issues. First, the company needed to find a way to simplify the battery pack and eliminate modules. Next, without the skateboard, Tesla needed a new way to shore up the structural integrity of the vehicle. What they ended up doing is turning luggage into structure the same way that an airplane has made fuel tank–shaped wings rather than wings that have tanks inside.
In some ways, it’s the same trick Tesla has applied to its starship design, where the body itself is part of the fuel tank. This is also not the first time Elon has applied lessons learned in one company to the products of another. In this case, the solution was a glue (material substance pun intended) that not only acted as both glue and a flame retardant as it did in previous models, but also as a material to strengthen the pack. Sandwich that between two steel sheets and you make the battery pack rock solid and shear resistant. It no longer requires outside support. Unlike CATL, which has started putting cells in the pack directly and eliminating modules, this is practically a cell-to-vehicle solution, since the battery pack is no longer just an enclosure, it’s part of the structure of the vehicle.
Tesla’s new pack kills more than 2 birds with one stone, though, because there are a couple of other things this new architecture enables. Now, without the battery pack extending to the front and the back of the vehicle, it has even more effective crumple zones as well as more room. This leads us to yet another benefit. Sure, that extra room could be left empty and used for more luggage. Or, perhaps, rather than a bigger frunk, the vehicle could get a large HEPA filter enabling bioweapon defense mode. Even with the HEPA filter, there would likely still be a larger frunk than today. It is hard to overestimate just how much extra room there will be, and part of that will likely even extend to a larger cabin as well.
The end result? Tesla was beating around the bush a bit regarding how much more effective the structural integrity was. During Battery Day, Elon Musk touted it as a good solution for solving the structural integrity issues of cabriolet vehicles, but did not directly compare it to internal combustion engine (ICE) vehicles or his own existing vehicles. Until a tweet this week, that is, in which Elon — coincidentally, replying to my tweet — clarified that it is more rigid and a major breakthrough.