Quick Charge Practicalities

August 10, 2012

Mark D Larsen

Power Broker
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For a Fistful of Dollars

Having already waxed pedantic about the battle between SAE and CHAdeMO over a quick charge standard, I should clarify that, in reality, quick charging isn’t as practical a solution for driving long distances as some might think. Why, then, did I want a quick charge receptable in my Leaf? To occasionally take an overnight trip of, say, up to 200 miles from home.

Map to Lost Wages
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For example, a couple of times a year I would like to see a show and spend the night at a casino in Las Vegas. That is a 130 mile trip one way, and a significant portion of it at freeway speeds. Since quick charge throttles back after the battery hits 80%, and because it isn’t advisable to let the pack drop too far below 20%, this means that such stations should ideally be no farther apart than about 50 miles. Consequently, I am guessing that it would likely require two quick charges to travel from my home to Las Vegas, probably in Mesquite and Moapa, as suggested on the map to the left.

Those two quick charges would extend the usual two-hour trip to at least three hours, but that's okay with me, especially since I gain an hour on the clock when crossing the Nevada border. In Las Vegas there are now several casinos that offer free L2 charging for their guests: the Mandalay, Crystals at CityCenter, the Mirage, the Flamingo, the Rampart, the Marriott. I believe that Penn Jillette has convinced the Rio to also install EVSEs, because he drives a Leaf. Ergo, plugging in my Leaf overnight while staying at one of those hotels wouldn’t be a problem. And I could use the same two quick charges to return home the next day, again adding an extra hour of travel time.

The key question is... IF someone installed those quick charge stations in Mesquite and Moapa, what would they charge? I can drive the round trip in my Subaru on a full tank of gas, which costs: 260 miles / 23 MPG (highway) = 11.3 gallons x $3.699/gallon (today’s lowest price here) = $41.80

If a quick charge during peak daytime hours has a price of $15 (like NRG is proposing in CA), driving my Leaf instead would cost: 4 quick charges x $15 = $60.00

At NRG’s “middle” rate: 4 quick charges x $10 = $40.00

At its “lowest” off-peak nighttime rate: 4 quick charges x $7 = $28.00

Now, IF these back-of-the-envelope ‘guess’timates were to ever materialize, then I suspect that most consumers here would gladly take a Leaf to Las Vegas at the off-peak price, and possibly even the middle price, but at the peak price... they would likely opt to take an ICE instead. It would save them a few bucks and shave an hour off their trip each way. Of course, I am no marketing expert, and perhaps I am making erroneous assumptions about consumer attitudes, but I have the impression that most customers fully expect that driving an EV is supposed to save them money. At least this is what we’ve been telling them for many years now.

Consider: they are already paying a premium price for an EV, sometimes twice what a comparable ICE would cost. A key part of the sales pitch to convince them to take that deeper plunge has always been that the operating costs are then so much less: very little maintenance and an EPA fuel economy rating at highway speeds of... 92 MPGe for a Leaf, 99 MPGe for an i-MiEV! On average, that's about 2¢ per mile, less than $2 to charge the battery from empty to 80% in the convenience of their own garage overnight. Given the rising gasoline prices, we’ve now got their attention!

So... “what's the catch?” they ask. Well, an EPA range of only 73 miles per full charge at best, but... that's more than most drivers need on a daily basis. Besides (and here’s the clincher), with the standard quick charge port on the SL model, they can recharge the battery to 80% in less than 30 minutes, if and when they do want to drive over-the-river-and-through-the-woods to visit grandma. And how much does a quick charge cost? Um... well... during peak daytime hours... er... actually... more than gasoline.

I suspect we’ve now lost most shoppers’ interest. Nor will it convince them to reconsider by explaining, with all the facts, figures, and utility rates, how very expensive it is to install, maintain, and run those quick chargers —hence the hefty price. I guess I just have a hard time imagining that most customers would be willing to buy a more expensive car, with more limited range, with the promise of cheaper operating costs, and then pay more than for gasoline to extend that range when needed —no matter the justification behind it, and even though they will actually save much more driving an EV daily than they would spend twice a year on quick charges to visit grandma. Consumers who are still interested after hearing that price... probably have two or more cars and have already decided to just pile into the ICE for those longer trips.

Ergo, it seems to me that the success of quick charging boils down to a question of “The Price is Right.”

High Plains Drifter

Map to the North Rim
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IF “The Price is Right,” I could see EV owners in my city using quick charges for the overnight trips to Las Vegas described above. I can also imagine vacationers opting to rent an EV to travel the 160 miles from the St. George airport to the North Rim of the Grand Canyon —which would probably require 3 quick charges each way, in Apple Valley, Fredonia, and Jacob Lake, as illustrated in the map to the right. In point of fact, I have already verified that a full charge will get them to Zion National Park and back, although a quick charge at park headquarters would make an EV rental even more attractive.

In truth, however, I actually think it is a moot point, because battery improvements will probably make 200-mile ranges possible long before out-of-the-way spots like these ever have quick charge stations.

Beyond that, I cannot imagine that, even with quick charging, many Leaf owners would be willing to drive truly long distances, such as when we visit my in-laws in Lincoln, California. That's a 700 mile trip. By my estimates, it would require about 30 quick charges round trip —provided there were, in fact, sufficient quick charge stations along the route. That's $375 at NRG's daytime $15 rate, yet only $225 for gas in my Subaru. Add to that the additional 15 hours of travel time merely for quick charging. In fact, it would probably necessitate extending the trip over several days: I typically drive it in only one, sometimes two, in our Subaru, but quick charging too many times in a 24 hour period can wreak havoc on the battery's longevity.

The basic rule of thumb should be this: use the right tool for the right job. We don’t use a sludge hammer to hang a picture on a wall, nor do we use a regular hammer to break up a slab of cement. It would be silly to fire up the oven to warm a burrito, and equally foolish to try to cook a thanksgiving turkey in the microwave. Don’t carve that turkey with a chainsaw, and don't cut firewood with a kitchen knife. By the same token, use an EV for 95% of your driving, day in and day out, with quick charging for an occasional 200-mile day trip. Beyond that, however, at least until batteries have improved enough to allow truly comparable long distance ranges... take a plane, train, your backup ICE, or rent a hybrid.