[Stupendous]

The beauty of this is that with battery technology rapidly improving, and performance for new batteries much better than older ones, Tesla's cars can retain or even increase their expected mileage per charge over the life of the car.

The expected lifespan of their batteries right now are about 7 years, but as anyone with a smartphone or laptop knows, battery life decreases rapidly over the life of the product. Tesla's cars were no exception to this and although most of the cars on the road are new and have not faced these issues yet, they were bound to crop up in the future. With battery swapping they've nipped this problem in the bud. Of course they'll charge you the difference for a newer battery but the benefits far outweigh the costs, and breeds stronger brand loyalty.

[sounds]

I'd really like to hear more about what this means, from the article:

  Frenzied drivers will still have to do some work though —
  they’ll have to drop off the battery on the return leg of
  their journey and pay an unspecified “transport fee”, ...

A legitimate worry is that you'll end up with someone else's lemon battery. Is the article referring to a Tesla mandate that you come back for your "original" battery, and how long do you have before you forfeit your battery?

[zanny]

The way you would want it done is as long as you own the car you pay some annual fee for battery swaps but then you can swap whenever you want. You would have to sign up at the point of sale for the service and not be able to situationally opt out whenever you weren't driving long distances with a desire for swaps though, because the idea is that you subsidize the fact you never need to "replace" your battery now and Tesla needs to keep up battery stocks with some fraction of the cost each year.

[TheAnimus]

>A legitimate worry is that you'll end up with someone else's lemon battery.

I was under the impression that these battery packs had so much monitoring and control technology built in, that would be very unlikely. Most batteries become lemons because on of the cells dies a death, becoming a short, which in turn drags down the other cells.

Tesla have a battery technology which is ment to be very advanced at managing each cell to prevent them catching fire, I would imagine they have very accurate wear level information on them too.

[InclinedPlane]

You left out the other part, which I think is significant:

   ... though they can also choose to keep the battery and pony up the 
   difference between the price between of the old and new batteries.

It's hard to say how much of an issue that is going to be without knowing the typical prices. Also, it needs to be balanced against the fact that a typical supercharger recharge is free.

[deletes]

I think the station will only house the newest version of the battery. You will not get your old battery back on the way back, as some explain, but you will get a new random battery every time. That is why the service is not free.

When battery technology is upgraded they will switch the entire stock for a new one. So there will be no anxiety for getting an old one.