EV-1 Frequently Asked Questions

Like all EV drivers, I get my share of questions from curious passers-by, especially at public charging sites in popular shopping centers like Mission Valley Center.

Here are the ones I get, in roughly decreasing order of occurrence. I usually get the same questions, but a few have surprised me -- especially when they're asked more than once by different people.

How far can you go on a charge? [By far the most popular question]

GM said 79 miles for my Gen 1 with Panasonic Pb-A batteries, but I never saw that. Nor would I want to push it -- the batteries live longer if I don't discharge them completely. Around San Diego, with its many hills and canyons, an estimated range of 55 miles is more typical. I might see 65 in careful freeway driving. But I rarely go more than 20-30 miles without a chance to charge, so I never really have to push the range limit.

My Gen 2 EV1 with NiMH batteries typically gave me 100 miles around San Diego and 125 or so on trips out of town where it's much flatter. We drove it to Disneyland a few times without stopping, charged it in the garage at the park while we played, and drove home on their electricity.

In my personal opinion, people put far too much emphasis on range and not enough on charging speed. Faster (and more) chargers can in practice largely overcome limited range-per-charge. Given the many setbacks in developing significantly better batteries for EVs, deploying lots of fast public chargers seems like a good hedge bet. They'll be needed anyway for trips beyond the range of whatever batteries you have. There may not be many public chargers now, but they're inherently cheaper, safer and easier to install than gas pumps.

To illustrate this point, I ask about the longest trip someone has made in their regular car. The usual answer is "cross country". I then ask how far their car can go on a tank of gas. The usual answer, if they know, is somewhere in the 300 to 500 mile range. "Then why", I continue, "aren't you demanding bigger gas tanks in your conventional cars?" The answer is obvious: gas stations are plentiful, and it only takes a few minutes to refuel. Only those driving in rural Alaska or Canada far from civilization -- and perhaps those trying to outrun the police -- really need maximum range.

By the way, the equivalent "charging power" of a typical gasoline pump is about 20 megawatts -- that's the heat power you'd generate if you ignited the gasoline as it comes out of the nozzle. Even if you account for the usual 20% (peak) efficiency of a car engine, that's still 4 MW. The "standard" Magnecharger for the EV1 puts out 6.6kW. See why we need faster EV chargers?

How fast can it go?

80 mph. Of course, that's its rated top speed -- I would never think of exceeding the 65mph limit around here. And you wouldn't go very far at that speed anyway -- range really suffers because drag increases faster than speed.

According to Popular Mechanics, it'll do 0-60 in 7.6 sec. Naturally, this is another test I wouldn't conduct myself. But I have screeched the tires on dry pavement once or twice -- accidentally, of course. I guess that means the EV1 isn't really a "zero emission vehicle" -- not with all that smoke from the burning tires...

How much does it cost?

It leases for $399/mo. You can't buy it. The conventional wisdom for the lease-only deal is that GM wants the option of scrapping the EV1 in a couple of years and replacing it with a totally new design without having to indefinitely stock parts and train technicians to support the relatively small number of existing EV1s.

Another theory is that having to return the car after three years discourages us technical types from enhancing it or trying to learn too much about how it works. Unlike the modern computer industry, which has finally discovered the benefits of open systems, GM is still very much an old-school car manufacturer. While there are significant advantages to an EV produced by a major manufacturer like GM (crashworthiness, good service support, etc), their closed, proprietary and "dumbed-down" approach is, to me at least, a definite drawback.

What colors can you get?

Blue, green and red.

How long does it take to charge?

I used to quote the GM figure of "up to 3 hours" for a full charge, explaining that the charging power tapers off as the battery fills so this is not quite as bad as it sounds. Now I usually look at the PilotDash, read off the battery charging current and say "The nominal usable pack capacity is 48 amp-hours. You figure it out." Sometimes I'll say that a good rule of thumb is two hours of charging for each hour of freeway driving.

How do you pay for a public charge?

It's free. This one surprises and intrigues a lot of people, so I hasten to add two things. First, I'd be happy to pay a reasonable fee to use a public charger if that meant there'd be more of them. And second, don't buy an EV expecting to save money - at least not yet. The cars themselves are just too expensive. And many of the associated costs of a car are direct functions of its original cost, including sales taxes, registration fees and comprehensive and collision insurance. There's a 10% federal tax credit and a $5,000 local California incentive on EVs that's factored into the lease price, but it's still more expensive than a comparable gasoline car.

There are moves afoot in the California legislature to provide some much-needed relief here by taxing EVs according to the value of a comparable gasoline car, but it's not law yet.

On the other hand, EVs are still high on their learning curves. Conventional cars have bottomed out on theirs and are now coming back up, thanks to the increasing complexity of emission control systems and, inevitably, the rising cost of gasoline.

How much does it cost to charge at home?

Depends on when in the day I charge it. I have a special Time-of-use rate from SDG&E. It gives me cheap electricity in the mornings and evenings and very cheap electricity after midnight, but very expensive electricity during summer afternoons.

When I was on the standard SDG&E Domestic Rate, electricity for my EV-1 cost about $.03/mile. If I set the timer on my charger to kick in at midnight, it costs me about $.01/mile under the TOU rate. This compares to about $.04/mile for a typical gas car (30 mpg @ $1.20/gallon).

That said, electricity costs per mile are probably small in comparison to the battery depreciation costs. The EV1's lead-acid batteries have an estimated lifetime of only 30,000 miles, and while they are covered by the warranty included in the lease GM still has to recover their replacement cost from lease revenue. On the other hand, the rest of an EV is inherently much more reliable than a comparable gasoline car. Barring serious design deficiencies, batteries and tires are expected to be the only significant maintenance expenses for an EV.

Can't you just carry a spare battery or something in case you run out?

This one really took me by surprise the first time I heard it. I was even more surprised when I got it again from someone else. The answer, of course, is that 40% of the EV1's curb weight of 2970 pounds is batteries. If somebody could make a portable battery that could store as much energy as the EV1's lead-acid pack (16.3 kW-hr), they'd totally revolutionize not only the automotive industry but many other areas of electronics. It would be one of the most significant inventions since the transistor.

I guess this question shows how we've all grown accustomed to the incredible energy density of ordinary gasoline. Burning a gallon of gasoline generates about 125,000 BTU, or 36.63 kW-hr of heat. By that measure, the EV1 has a "gas tank" that weighs 1175 pounds (over half a ton) but holds only half a gallon.

A fairer comparison would account for the inability of an internal combustion energy to turn more than about 20% of that 36.63 kW-hr of chemical energy per gallon of gasoline into mechanical energy. A storage battery and electric motor is roughly 4 times as efficient in "burning" lead, so the "equivalent capacity" of the EV1's half-ton "gas tank" is more like 2 gallons. That's just about right considering its 55-60 mile range and that a gas car of comparable weight and size would probably get 25-30 mpg.

Can't you put a solar panel on the roof to charge it?

Let's do the numbers. Sunlight on a clear day is about 1 kW/square meter on the earth's surface. A good solar panel is about 15% efficient in converting sunlight to electricity, so a 1-square-meter panel in full sun will put out about 150 watts.

GM advertises this car as getting 4 miles per kW-hr, which seems about right. So the equivalent charging "speed" you'd get from a 1 m^2 panel (approximately the EV1's roof area) is 4 * 150/1000 = 0.6 miles per hour. And that's the very best you could do, with the sun shining directly down on the panel. In clear weather in subtropical latitudes, you'll get the equivalent of maybe 4 hours of direct sunlight per day. That works out to 0.6 x 4 = 2.4 miles per day. Not much.

Some people do charge their EVs with solar power. Actor and EV1 driver Ed Begley, Jr. is a well-known example. And there are several "solar EV charge ports", most constructed by government agencies as demonstration projects. I've seen the one at the South Coast Air Quality Management District in Diamond Bar, and one at the San Diego County government administration building. But all these facilities consist of large fixed solar arrays -- much larger than an EV1 -- connected to stationary chargers. The SCAQMD and San Diego facilities are "grid tied", meaning that the solar arrays pump power back into the utility grid while the EV chargers draw power from the grid; there is no local battery storage. Depending on how much sunlight is available and how much EV charging goes on, the site may be either a net consumer or a net producer of electricity at any given time.

Won't the batteries run down if you're stuck in traffic?

The car draws very little power when stopped, as an electric motor does not idle like a gasoline engine. There's no clutch, so with the car in drive and the brake pressed to hold the car, the propulsion motor is stopped and draws no power. Power still goes to the control electronics, the coolant pump, the running lights, the power steering pump and the radiator fan -- the last two running only as needed. Also, the headlights, HVAC and other accessories may be on. But even the air conditioner and headlights draw far less power than the propulsion motor when the car is accelerating or overcoming drag.

In fact, the car often gets better range in slow traffic than at fast highway speeds because drag increases faster than speed. Also, usable battery capacity increases at lower rates of discharge.

Back to Phil Karn's EV1 page

Last updated: 2 June 2011