Oh, come on. First World Problem: "My new pollution free cars fills at home, but on the few occasions that I have to go out of my way for energy it takes 10 minutes to refuel instead of 2."

You're ignoring the substantial problems that battery swapping introduces – it introduces issues of standardization, compatibility between cars, more moving parts, more weight, additional vehicle design constraints, and creates enormous inertia in battery technology. It constrains innovation. No company can come out with "The 2021 Leaf, now with 15% denser batteries!" without fragmenting the shared supply of battery packs.

I admire Shai Agassi's business model, everyone seems to be fixating on the battery swapping aspect. It's incidental. The real innovation there is using the cell-phone business model on electric cars.

Imho, an alternative solution with fewer drawbacks would be offering "on-shore" cooling by exchanging a fluid coolant through the charge connector. The charge-rate constraint isn't really the batteries, it's how fast you can cool the batteries. With offboard cooling you could charge a ~300 mile range EV in about 3 minutes without over-sized onboard cooling. You're also more likely to find a use for the waste heat offboard, e.g. melting ice or preheating water.

The down-sides of this system are small – any sufficiently high-current "cable" would already be mounted on a "weightless" articulation rig, or a robotic solution that plugs in automatically when you park (Shai Agassi has been working on this technology).

I.... I just don't know what to say to this.

Except maybe "Good luck."

Once battery capacities reach the point where you only have to charge it at night for a full day's drive, you've solved the problem and you don't need to swap.

And, while the price tag is high, the 300 mile claimed range of the highest trim Model S gets a substantial part of the way to that standard.

Perhaps that's true... once batteries get about 2x as good as they are now, owners of cars like the Tesla won't have to worry so much about whether there will be power available at their destination.

My impression is that the next 2x improvement in battery tech is pretty far over the horizon, though. Plus, we simply do not have the grid capacity to replace most Americans' automobiles with rechargeable EVs. Not even by charging them at night. Once 80% of the houses in your neighborhood plug in an 8-kw load at night, this inconvenient truth will become obvious enough.

Exchangeable batteries could be charged anywhere, anytime, not just where and when they are needed. That's a big win regardless of what happens with the core technology of power storage.

Modern batteries (LiFePO4) can be charged in 10-15 minutes. I know I'm going to want to walk around for 10-15 minutes after driving for 120 miles. Heck, that's even the recommendation to avoid DVT!

High range is one way to solve the problem. Fast-charge is another.

This is not a valid analogy.

Sure, you can. When's the last time the battery display on your laptop or cell phone lied to you? Battery monitoring tech has been reliable since the lead-acid days, and it's only gotten better over the past few years.

There'd be some redundancy in most cases anyway. A sports car might require two or three standard battery units, each of which would consist of numerous individually-monitored cells. An 18-wheeler might require thirty or forty of the same standard battery packages, or perhaps ten of a larger form factor (think 'AA' versus 'C' or 'D'). In both cases the vehicles would be able to limp on half-power or less, in the event of battery failures.

This objection is a complete non-starter, no pun intended.

Edit: By the way, those swappable battery modules are going to last a lot longer since they won't need to be fast-charged.

This is probably the kind of thing that would need to be done by international agreement, if it can be done at all.