Here is a theory I'd propose: It seemed as if Elon ruled out a ultra-capacitor at the Shareholder meeting. He indicated that there were still issues with the technology at present. If that's the case, than the Frunk battery doesn't seem to be in the cards yet.
What if the June 20th announcement is a battery swap demo, but the twist is this: If you buy into the battery replacement program Tesla has (even though they have announced it, I don't think you can actually buy into it or get any real details), you get access to unlimited battery swaps and are guaranteed to get the best battery available. I would assume that with the level of data the car reports, the health of the battery is relatively easy for Tesla to determine.
The overall strategy would look like this: You want to take a road trip, you start out with your battery at a standard charge (Approx 90%). You go to a Supercharger and use that to get to your destination. But once you are there, instead of hunting around for a charging station and worrying about what your state of charge is, you roll up to a Tesla service center (I think Elon said they will have 75 open by the end of the year), then you do a swap out for a full battery pack in just a couple of minutes and are good to drive all around the city without any worry. When you are done visiting the city, you do another swap for a full pack and drive point-to-point via the Supercharger network and get back to your home. There you can either swap out the pack for a full one or just go home and charge. Tesla monitors the pack and guarantees that they will swap you back a pack that is about the same as your original one.
Maybe that's part of the reason there aren't that many Superchargers on the map in major cities (Where the service centers are). I would think all you would need would be a jig of some sort to swap the battery and you wouldn't need to carry that big of an inventory of battery packs to cover the swaps since each car would be leaving their pack behind in a swap. Storing 10 battery packs in a service center would not take up that much space since the packs are in a nice form factor. Cost would potentially be an issue, but with the capital they just raised (Elon said they have about $760million in cash now) they could build out the pack inventory.
Just a theory, but it seems like a more elegant one that combines battery swapping and the Supercharger network to eliminate a big hurdle to the longer range travel argument. I know there are big concerns people have about swapping their pack for one they have no knowledge of, but I would think Tesla would have good enough data to tell you what health your battery is in and find a way to alleviate the concern that you would be getting a pack worse than your original pack. I don't know how they will handle a 60kWh car vs. a 85kWh car, but this is just my dreaming about what might happen, so I won't try to solve every issue in this post!
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