Renting an extended range battery...is it an option?

There is a sticky on this topic over in the Model S section:
http://www.teslamotorsclub.com/showthread.php/2496-Removable-swappable-pack-options

Fr23shjive said:

Is that just a rumor, is it a possibility, or has it been confirmed?

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My opinion on this is to regard anything that is not on the Model S page as just rumor and speculation. Also at this point in Model S development, don't take anything even on that page as confirmed.

Given those caveats, "1 minute Battery Swap" is listed on the Model S spec page: http://www.teslamotors.com/models/specs
Also, the recent media tours of the Tesla factory showed the engineers are still designing the pack to be quick swappable.

However, there are still no details about the terms under which swapping will occur, so if it is critical to your purchase of the car, I would wait for more details on that before making a deposit.

Two points

If Elon says it, it's much less rumor than from just about any other source.

The Roadster battery does not come out nearly as easy as it could. I'm sure that having this critical component (of three) be easy to remove is just good design for maintenance even if they do not go with hot swapping.

Latest I heard was 5 minute swap, but the rental idea is a good one. If Tesla was actually planning
such a thing, you'd think perhaps they would have designed the battery pack so that it would simply be
extendable, so that you would only be renting an extra so many cells. Another possibility, if they have
the room, would be a mega extension, resulting in perhaps a 100 kWhr pack with 450 miles of range.
When you think about it, close to 300 miles with an hour recharging during lunch and another near 300
miles and a slow charge overnight isn't inconveniencing the traveller very much.

I am curious about this quick battery swapping thing. If the battery pack is going to be an integral part of the unibody structure, I simply don't see it being a 5 minute process to remove it and install a new one. They're going to need to be a little more diligent than that, given the role the battery pack plays in the chassis. The whole car would need to be stabilized in a jig of sorts to prevent any body movement.

I remember reading about the early 4th-gen Corvettes that you sometimes couldn't put the removable targa panel back in if the car wasn't sitting on level ground! Now, I don't mean to suggest that an 84 Corvette is in any way comparable to today's cars (chassis rigidity has come a loooong way), but with the battery pack being the dominant structure in the chassis of the car, I think you can get the idea. I would think more like an hour or so for the whole process of a battery swap.

I have no idea but I guess there's a large aluminum panel fastened with 4 or 8 bolts to protect the batterypack itself. So put it on a jack, remove the panel. That gives access to the bolts locking the battery in place or some quick-release locking lever thingy. Remove the battery, roll in a new one, raise it into the hole make sure it hits the socket, and secure it back up with the bolts or levers. I suppose you need to relase the battery from the cooling connections as well. Remount the protective panel and you are ready to go.
In many ways I'm thinking this is a bit like changing a tire with a hubcap protecting the bolts. A VERY heavy tire that doesn't roll as well, but essentially the same kind of process. The tire is an essential part of a car's structure as well and since the weight is lower we are fully qualified to change them ourselves.

Cobos

I get what you mean that the battery is merely bolted in. What I'm saying is that if you just jack the car up, and then remove what amounts to the frame, the car will no longer be structurally sound, and will flex, making reinstallation of the battery pack ("frame") difficult. Yes a tire is essential, but not part of the structure of the car itself. Ever notice that when you change a tire, if you jack up just one corner of the car, that it takes a bit of jacking for the neighboring corner to rise off the ground? That's chassis flex. Remove the Model S's battery pack and you will be dealing with a lot of it. So it'll be a bit more complicated that just jacking the car up, I believe.

mattjs33 said:

I get what you mean that the battery is merely bolted in. What I'm saying is that if you just jack the car up, and then remove what amounts to the frame, the car will no longer be structurally sound, and will flex, making reinstallation of the battery pack ("frame") difficult. Yes a tire is essential, but not part of the structure of the car itself. Ever notice that when you change a tire, if you jack up just one corner of the car, that it takes a bit of jacking for the neighboring corner to rise off the ground? That's chassis flex. Remove the Model S's battery pack and you will be dealing with a lot of it. So it'll be a bit more complicated that just jacking the car up, I believe.

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#1: You don't drive the car without a pack. The chassis is probably plenty sound to hold its' shape without a battery pack. Why do you make some conclusion that re-installing a battery pack would be difficult? My assumption is that the chassis would have no problem holding its' shape and be ready to accept a replacement pack if you ever had to repair it or upgrade it.
#2: When you jack up a car on one side the suspension on the other side starts to accept more of the weight and starts to compress. I think the affect of chassis flex isn't the (main) reason why the other side doesn't rise in unison. Again, I think you may have some mistaken assumptions.

See http://www.teslamotors.com/blog/tesla-vehicle-engineering. Video #3 discusses the battery pack's rigidity. The first and second video mention the space frame's rigidity. I can't find the reference now, but I distinctly recall a video mentioning 30+ bolts holding the two together.

Yes, the pack adds rigidity... But that doesn't mean the frame falls apart when you take the pack out!

TEG said:

Yes, the pack adds rigidity... But that doesn't mean the frame falls apart when you take the pack out!

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IIRC, Peter Rawlinson talks about the pack in the engineering videos. He mentioned that the chassis is very rigid by itself but adding the pack triples the rigidity.