[baybal2]

E6 is an interesting case

It's freaking heavy at 2t. It's not that small or aerodynamic. It's battery pack is definitely behind leaders in net capacity.

What makes it run that long is that they don't overprovision the battery that much, so much more of those 60kwh is available for driving.

In addition to that, BYD uses PM BLDC motors that are better than induction motors at doing regen at low and very low speeds, which is much more important for city driving.

Add to this that their battery and electronics can take more regen current, and do it more efficiently.

[gruez]

>What makes it run that long is that they don't overprovision the battery that much, so much more of those 60kwh is available for driving.

there's a reason they overprovision. the battery is going to wear out way sooner than their competitors.

[baybal2]

They specifically use a battery chemistry with very high cycle life and high current tolerance just for that.

[gruez]

Interesting. Is there a reason this technology isn't used by competitors? What are the downsides? Is it their "secret sauce"?

[baybal2]

BYD owns the biggest factory for LFP batteries around. That's point one

The biggest downside is its lower specific energy, but it is compensated by all of things above, so the net capacity and energy density comes close to other chemistries. However, working around all of those "sharp corners" requires a very different engineering approach from mainstream EVs. So that's a second point. Competitors largely don't bother going deep with engineering.

The engineering philosophy there is much closer to their electric busses. Much more manufacturing conscious, with a lot considerations for commercial use.

They think of heavy users who will use the battery for 2k+ cycles with minimal service, and go through multiple battery packs through the life of a vehicle.

[mikekchar]

I bought a used 2016 Leaf with the idea that I could use it for the next 5 years or so and then upgrade to a car with larger capacity (my car is only 30 KWh). Out of curiosity, I asked the sales person how much a new battery would cost in case I had problems: ~$7K. At that price (and assuming it's installed price... I forgot to ask), I might actually be tempted to do do a battery swap after the 5 years if the car is otherwise OK. However, it seriously doesn't look like I'll need it. After a year of use, the battery capacity doesn't seem to have moved at all. In the summer on the slow roads around here I even get about 230 km (~140 miles) range on that tiny battery, which is quite a bit more than I was expecting.

So with all that said, I wonder if they are on to a good idea. There is so little maintenance on these EVs that the occasional battery swap might be fine, cost-wise. You could even sell it upfront in installments -- new battery after x years.