Stalled Out on Tesla’s Electric Highway

A relative gauge or percentage would be one thing, but if you tell the driver it's going to get 100 miles, they need to know it can make that to the next charging station.

If EVs become common, people will have home charging stations. Demand for non-at-home charging stations will come from (1) folks who drive a lot and need to charge intraday (and who cannot charge at work) and (2) road trippers. The sum of both of these categories is fairly small and less demand means less supply. So if you do fit into one of those two categories, you will need to plan your driving carefully instead of figuring that you'll be able to pick up some gas when you need it. This can be overcome by arranging for the proliferation of public EV charging stations even absent the demand. Perhaps the manufacturer or municipalities will subsidize it.

Showing that the range is zero when the battery is dead is not hard. The problem is when the displayed range drops faster than you're traveling, and if that wasn't the problem, he wouldn't have been stranded. If it was adjusting its display for temperature, it wouldn't have been wrong.

Or, they could provide what a lot of east-coast cars have, a built in engine-block heater that you plug in to a 110V extension cord overnight.

Had he plugged the car into a 110V outlet overnight, the battery would have been charged in the morning.

You can do electric heat via heat pumps, but it requires more equipment and it doesn't work if it's too cold. You can get about a 4 to 5 advantage over plain resistance heat.

Gasoline engines lose a lot of energy to waste heat -- but sometimes that waste heat is exactly what you want.

Battery capacity is, though, just like it is something you think about when driving a petro fuel car. Drive a diesel? You need to think about gelling fuel in Vermont in January. For a supposedly well educated technological society, an awful lot of us seem to engage in magical thinking.

So, I've been reading the forums at teslamotorsclub.com recently, and there are a lot of questions (and answers) about the Model S's range. From what has been written over there, it sounds like the car's speed has the biggest impact on range. In the NYT piece, I notice that the only time he mentions his speed is after it started to look like he might not have enough range to make it to his destination--and then he only mentioned how slow he had to drive. I would submit, then, that an "experienced early adopter" would know that his driving speed matters and therefore not try to drive down the expressway "upside-down at mach 3 with his hair on fire."

I also notice that the author made no attempt to charge the car at his destination in Connecticut. Instead, he planed to rely exclusively upon Tesla's "Superchargers" for the entire trip. Again, an "experience early adopter" would know that the Model S can be plugged into a clothes dryer outlet and fully charged overnight (i.e., no waiting). He could have started his second day with a fully-charged battery, if he chose to. Actually, the author probably would have had enough range for the rest of his trip if he had even plugged into a standard 120V domestic outlet in Groton.

Frankly, it sounds like the author was trying to make his life difficult. Almost a third of the verbiage is devoted to range problems that were a direct result of his decision not to charge in Groton. When drivers choose not to fill up before driving across Death Valley, do we blame the driver or the car?

This isn't to say that the car is ready for prime-time. After all, the author may be representative of the general public. However, I think that anyone with even a modicum of curiosity about his new car--and more importantly, someone who, by purchasing one, had some sort of incentive to make things work instead of writing a diatribe in the NYT--would have no trouble figuring out these things, and avoiding the range problems described in the article.

Swapping my car's battery should be as big a deal as swapping the propane cylinder on my gas grill.

And yes, batteries these days are perfectly capable of monitoring themselves in a leased-usage scenario. Your laptop battery has its own CPU and EEPROM, for instance. To understand why, see any recent news story on the Dreamliner.

Of course, without an industry-wide effort to standardize a few core battery sizes for different applications, it's a moot point. That is the problem that I wish Musk had set out to solve.

It's just that for the majority of people, battery swapping makes no sense. They can charge their vehicle over night at very very cheap prices and have enough range to serve them all day. If you insist on taking a cross-country roadtrip, rent an ICE - the infrastructure is just not there yet (or peoples minds have not accomodated - see this article).

My thinking is that they would be kept on trickle charge at the gas station after delivery. That wouldn't take a huge amount of power. The actual recharging process would happen at a depot that has high power connectivity to the grid with low distribution losses.

I suspect it would be more efficient to do that and have the charged batteries trucked to the service stations, than it would be to have each service station do their own primary recharging. Especially since, as you say, the service station owners aren't going to want to devote a huge amount of space to battery inventory.

I'm vaguely aware of Better Place but they certainly don't get Tesla's mindshare (good, bad, or otherwise.)

I bet he probably could have gauged it by jumping in the car turning it on and then starting the heater as well. His mileage would have declined before he even started driving.

Think of it this way, batteries always improve in 2nd / 3rd gen devices (look at apple) and I am sure that is what Tesla will start to address.

- Have the reporting system look at current temperature and change the reported range.

- More supercharger stations closer together. (200 miles apart for a reported range of 268?! Ballsy. Especially in the extreme cold of the northeast. Reckless when you are giving a car to a NYTimes reviewer.)

- Don't have the parking brake LOCK so you can't even move the car without a flatbed truck.

- Have the car warn/inform the driver when they park somewhere cold to keep it plugged in to warm the battery up

and that's off the top of my head.

Many things can be done. This isn't necessarily a 'physics problem.' It's communicating and setting expectations. When the car says "100 miles" and you are stuck at the side of the road after 50 miles, it doesn't matter that "the physics make sense". What matters is you were screwed by completely false information.

The fix is simple. In fact, it's so simple, I would be SHOCKED if the TSLA guys aren't already including it in a future firmware update.

Obviously, lithium batteries are going to lose charge in colder weather - that's just physics, but the problem here was twofold: one, the inherent limitation in the battery itself, but perhaps more importantly, how the car reports available charge to the driver in those conditions. If the car tells me that I have 100 miles to drive, I should have 100 miles left to drive. That it does not is a design flaw, and one that should not have been overlooked, plain and simple.