Tesla may be tanking the EV industry

[jaded]

@mmascari

This is pretty close, in that it should create a larger volume of vehicles all using the same form factor battery. Only one manufacturer not an industry standard though.

I don’t think most people were thinking swappable in the “do it at home or at a station instead of charging the car” scenario. More of a “these 10 vehicle models all use the same form factor and sold a substantial volume so there is a market to produce third party replacement parts that a mechanic could swap”.

More like a shared transmission or gas tank part that is used on multiple vehicles. Not something you swap often or at home. Something a mechanic would do and a replacement part is available because it was used in enough volume to create a secondary market.

I agree that “replacement parts” is more practical than “hot swap charge batteries.” I kind of went on a tangent there.

But even so, it’s too easy to think about the batteries as a fancy gas tank. The engineering reality is quite different. Making the packs in a few standard sizes to fit the available space seems like the easy part. But the physical size dictates other attributes like the pack voltage. In general, higher voltages are more desirable for reasons like faster charging and thinner wires. So the higher the voltage, the more cells are required to be in the pack, so the bigger it needs to be (and the stronger the frame needs to be to support that larger mass of cells.)

This also brings up a first sticking point: there is no agreement on what is the “best” voltage or power available in a pack. It changes based on external factors: battery availability, battery chemistry, charging station capabilities, etc. So manufacturers are still trying different packs, and while they tend to settle on a few values, those are still subject to change over time.

There’s also a sophisticated battery management algorithm needed to run the pack. It has to instantly respond to different kinds of inputs, like which cells are available to store the incoming power from regenerative braking, which cells are too hot or too cold, battery lifetime, etc. And that data has to be shared with the car, so not only does it need compatible electrical connections, but a compatible data structure.

This one is particularly tricky, because battery management directly impacts range, which is a huge differentiator for sales. If my car company develops the smartest, best battery pack on the market, I won’t want it to go into the competitor’s cars.

And as I mentioned before, they also require plumbing for heating and cooling. So all packs have to locate their coolant connectors in compatible locations.

It’s not that any of these are a deal-breaker for making an SAE-standard battery pack. It’s just that it’s a lot of cooperation between rivals that all would have to come together.