Battery Range: Yours Will Vary
By Noel Adams
This morning I was looking through my EV World news letter, and under the “Top Ten News Stories” section was a link to an article called “The Emperors New Cloths” written by Ralph Kinney Bennett in The American, The Journal of Enterprise Institute. This article quotes Tomohiko Kawanabe, chief of research and development for Honda Motor Co who expresses the opinion that electric vehicles won’t go main stream any time soon.
Honda, of course is notoriously pro hydrogen mostly, I suspect, because of the fueling time which can be almost as fast as a standard ICE vehicle. One comment of his struck me most strongly. “EVs—including the very best of them—don’t go very far. They go even less far if they go fast. They go even less far if they contain passengers or any significant cargo. Or if it is very cold. Or if it is very hot.”
A short time after I read this particular article I was browsing youtube and came across on old segment of the British car program “Top Gear” where Jeremy Clarkson test drove the Ford GT40. Top Gear is all about performance and speed so Jeremy Clarkson really pushed the GT40 on the track and eventually ran out of gas. The car, which is supposed to get 12mpg, managed just over 4mpg being driven hard on the test track and the 17 gallon tank managed to give the car only 75 miles of range, down from the 200 miles expected if the car is driven sedately.
Coincidentally, when Jeremy Clarkson test drove the Tesla Roadster on the same track, it too ran out of juice after 75 miles. When co-presenter James May tested the maximum speed of the Bugatti Veyron he noted that at top speed, the million dollar Veyron drained its 26.4 US gallon capacity fuel tank in 12 minutes which gives the car a range of just 51 miles.
The truth is that all of the factors mentioned by Mr Kawanabe will also affect the range of a normal ICE car. We have been conditioned over years of driving to watch the gas gage and when it gets down to a predetermined point we find a gas station and pump some gas into the tank. Unless you follow your mileage carefully you won’t notice that you are getting better or worse gas mileage over different driving conditions.
I did some tests with my Prius recently and I found that when I drive to work alone I get an average mileage of around 49mpg. When I drive carpool with 4 adults in the car my mpg drops to 44mpg. When it gets cold you crank up the AC and that takes fuel. The only thing that doesn’t impact gas mileage so much on an ICE car, although it does have some effect, is using the heater on a cold day. The ICE car produces a lot of waste heat as part of burning fuel to propel the car. This waste heat is typically used to supply heat to the cabin. That’s not to say that cold doesn’t impact fuel consumption. Living in Los Angeles I don’t really have to contend with cold weather, but other Prius owners who live in colder climates do notice a drop in mpg during the winter months and have found that partially blocking the air intake at the front of the car will improve mpg. Basically you don’t need as much air to cool the engine when it’s really cold outside so cutting air flow means the car has to fight the cold less.
There are still some things that you need to take into account before you plop down your deposit on an EV.
As Jeremy Clarkson found out, thrashing the car can reduce range by more than 50%. If you are going to drive a Nissan Leaf then driving the car flat out on the freeway is could mean that the 100 mile range is suddenly 40 miles. Driving the car like that is of course a choice. If you only need to go 10 miles each way then you might not be concerned about cutting your range, but if you need to drive 40 miles each way you will need to adjust your driving speed to make sure that you can get 80 miles. The RAV4 EV officially has a range of 70 miles but many owners have been able to go over 100 miles on a charge by driving like they have an egg under their accelerator.
If you are going to haul around the family then that will impact your mileage too. In a Nissan Leaf, the 100 mile range could drop to 80 miles if you are driving with a family of four and their luggage.
If you live in a hot climate like I do then you need to run the air conditioning during the summer. The AC will run even harder in desert climates like Palm Springs or Phoenix. I haven’t done any real experiments on this but I would anticipate that a Nissan Leaf running the AC full blast would see range drop from 100 miles to 80 miles. You can of course open the windows instead of running the AC. This will only be of benefit up to a point. Experiments with an EV1 showed that below about 40mph range was better with the windows open and the AC off but once the car went above 40mph it was better to shut the windows and turn on the AC.
Cold will also impact your range. In really cold weather running the heater will cut range quite noticeably. On a Nissan Leaf I would expect range to go down from 100 miles to about 75 miles. Again you have choices, you can bundle up and not run the heater or you can run the heater and take the mileage hit.
For both these situations cars like the Nissan Leaf provide cabin preconditioning. This will allow you to pre-heat or pre-cool the car while still attached to the charger using power from the grid. If this is done then the AC or heater only needs to keep the cabin at the preset temperature rather than having to cool or heat the cabin first and this reduced consumption from the batteries.
It’s plain to see that if you take your EV, fill it with passengers, load it up with luggage, crank up the AC, then hit the freeway at 80mph, you are not going to get very far before the range gage starts to flash low charge, even if your car is supposed to get 100 miles on a charge. On the other hand, if you drive alone, use heat and AC sparingly and learn to drive in a more sedate way, they you could get better than the expected range.
Given limited range and long charge times for an electric car, it bares some thinking about before you make the plunge. Keep in mind however, if you are an average driver, who drives alone to work with a round trip of about 40 miles then a 100 miles range electric car will work well for you. If you drive 60 miles each way and like to drive like a demon then you should probably think twice before giving up the old ICE car. It’s your decision and you need to be informed before jumping in, and buying an EV.
Most people won’t be using the next crop of electric cars for long trips, although plug-in hybrids like the Chevy Volt fix that issue, allowing the cars to be driven as long as you have gas in the tank. For pure EVs there are a few key issues that you should know about.
One thing that many automotive journalists who have, after all, spent most of their adult life around ICE vehicles, don’t seem to get, is that the ability to charge at home means that you leave each day with a full tank, or in this case a fully charged battery. Most Americans have a 220V or 110V circuit within 25 feet of where they park their car. So when they get home at night they can plug in their EV and it starts charging. Who cares if it takes 8 hours, they are fast asleep in bed. In the morning they are back with full range, in the case of the Nissan Leaf about 100 miles. They have plenty of juice for their 20 mile each way commute and more than enough to run a bunch of errands during lunch.
Another thing to that many people don’t grasp is that you don’t have to fill up the car each time you charge. If my wife gets a sudden urge to go to South Coast Plaza, a major shopping center about 50 miles south of where we live, it would be pushing things to go round trip to the mall in an EV like the Nissan Leaf, but guess what, South Coast Plaza has a J1772 charging station which is totally compatible with the charger that will be in the Nissan Leaf so I would be able to drive there and get a partial charge while my wife puts strain on the credit cards, adding something like 20 or 30 miles of range, and I would have plenty of juice left to get me home.
Clearly the electric vehicles about to make their appearance on the streets of the US aren’t for everybody but I have news for you, neither is the Toyota Sienna minivan or the Chevy Malibu, or the Ford Explorer. The cars will work for a good number of people and that will provide the sales needed to bring down costs and fuel further improvements in batteries.
First time buyers of the Nissan Leaf will fall into one of two categories. One group will buy the Nissan Leaf thinking that the 100 mile range is set in stone and will be disappointed when they find that they sometimes get less miles. They will wait for the car’s low charge light to start flashing then they be upset because they have to wait eight hours for a full charge – longer if they only have access to a 110V outlet. In the end they will sell the car and go back to an ICE vehicle. The other group, and I expect this to be the majority of buyers, will have normal driving patterns that are well within the capabilities of the EV. They will charge their car overnight so they have a full tank each morning. Eventually the EV will become their primary vehicle and the ICE will sit most of the time waiting until they want to take that long road trip. They will discover sites lik evchargernews.com which will allow them to find public chargers and this will greatly extend their EVs usefulness. In the end this group will never want to go back to driving an ICE.
In this article I have picked on the Nissan Leaf because it is likely to be the first of the new electric vehicles coming from a major automaker to be sold to the general public. However, what I have said above applies equally to the Ford Focus EV, the Mitsubishi i-MiEV, and any other pure electric vehicles that will soon be in a showroom near you.
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