The Electric Car

The Electric Car
Fall 2006

The recent announcement by General Motors of their latest electric car, the Volt, to be sold under the Chevrolet brand name, is of great interest. It is just about what I have been waiting to see, and I believe is a far better way to go than the Toyota Prius that has caused a bit of a stir.
To understand electric cars, whether one of several forms of hybrid, or a pure electric, you need to consider present battery technology.

Batteries

Lead Acid
These were the first practical rechargable batteries and are the familiar ones in present day standard cars as they have been for the better part of century. They allow the use of an electric starter, still their most important use, and that allows the use of large engines, impractical to crank by hand. This has allowed most anyone to start up a car, leading to the great popularity of them.

The lead acid battery has one set of plates made of spongy lead and another set of spongy lead sulphide. They use sulphuric acid for an electrolyte. Right off, you can see they are not the nicest things to have around. Lead is of course poisonous, and the mining, refining, and even the recycling of lead is a real problem. I have seen a recycling plant that was shut down because some lead was getting loose and contaminating the surrounding area. Sulphuric acid is unpleasant stuff to get on you or your clothes, or even on metal in the engine compartment. You used to have to add distilled water to the cells at fairly frequent intervals to make up for evaporation, but sealed batteries have pretty well taken care of that.

Lead is of course heavy. You might even say it is heavy as lead. The battery does not store much energy, and although it can deliver and recharge rapidly enough to make it useable, it is not outstanding. It also can only go through so many recharge cycles before the plates harden and it no longer can take a charge, requiring replacement. The lead can be recycled, but that is expensive and can cause pollution.

This is a mature technology (should be after nearly a century), the price is fairly reasonable, and the batteries are adequate for the needs of starting an engine and providing for electrical accessories until the engine is started. They will probably be around for a time, perhaps a long time.

NiCad
Nickel cadmium was the next step. These were sealed batteries and stored about twice the energy of lead acid. They were lighter. Unfortunately, they had a serious "memory" problem: if not fully discharged before recharging, they would not discharge past that point next time. NiCad batteries quickly went bad. Also, both cadmium and nickel are toxic.

NiMH
Nickel - Metal Hydride was the next step. They just about doubled the NiCad, or about 4 times the lead acid. They have a bit of the memory problem, but by charging for a long time, they can be pushed back to a full charge. They are still widely used in such things as cell phones. Their biggest problem is the nickel. Not only is nickel toxic, it is not plentiful and is needed for such things as stainless steel. It will remain limited and expensive, and NiMH batteries will always remain expensive and available only in limited sizes and amounts.

Lion
Lithium ion was the next step. They just about doubled the NiMH, or about 8 times the lead acid. Only a small amount of lithium is needed for the ions, the electrodes are made of various things. Lithium is non-toxic, and is even a trace substance apparently needed by humans. It is widely available and adds very little cost to the batteries, the electrode material and fabrication are the cost. Lithium is extremely light, but that is of no importance since so little is used, however the lithium ion batteries tend to be light. They have no "memory" problem and can often be recharged remarkably rapidly. They can be recharged many times before going bad and needing replacing.

As you can see, lithium ion has the makings of the ideal battery. However, there are a few catches. Mainly they can overheat if abused, sometimes even starting a fire or exploding. Part of this is a result of all that energy they are storing. If ever let loose suddenly, something bad will happen. Like a tightly wound spring let loose, or a tank of gasoline set on fire, all that energy suddenly released could be unpleasant.

They also can be ruined by discharging too far. They have to have logic circuitry either in the battery itself, or in the equipment using them, to control charge and discharge.

Advanced Lion
Something that can be called advanced lithium ion is being activly developed by a number of businesses. They are about doubling the Lion, or about 15 times the lead acid. They are fixing some of the problems with the origional Lion, and these are probably the batteries of the future, especially for electric cars. They can be fabricated in all sorts of sizes and shapes, which can be a real advantage to the design of the devices to use them as a large "battery compartment" does not have to be provided to fit whatever the battery is like. Instead, a battery can be designed to fit into whatever shaped space is available. The batteries do not need a strong case to confine the electrodes under pressure, saving weight and volumn.

History
Everyone knows that dumb old hide bound GM ignored hybrids and let inovative Toyota eat their lunch with the Prius hybrid. Some remembered that GM brought out an electric car, the EV1 back about 10 years ago, but then killed it to show it couldn't be done, so they could go back to the gas guzzlers. There is even a documentary movie out on it. Of course all this appeals to the people who are convinced that someone invented a carburator that would give a car 100 mpg, but a big oil company bought him out and quietly disposed of it.

They don't seem to remember what went on a mere 10 years ago.

California, long on dreamers and short on realists, passed a requirement that 2% of cars sold in California had to have zero emissions. An all electric car is the only way to get clear down to zero. General Motors spent a half billion of their own money (and another half billion of government (i.e. your) money) developing and producing a workable zero emission electric car. They were the ONLY manufacturor to do so. It was a bit expensive and not really practical yet, but was workable and met the requirement.

The others got California to change the rules, to the benefit of the gas/electric hybrids they had about ready, catching GM flat footed. With no advantage to the zero emission car, and it being a bit too expensive for the numbers, GM dropped it. A good part of the reason for calling them all back in (all 800 were leased) and scrapping them was the liability the government would hit GM with if anything went wrong with them. There was also the high per unit expense of supplying parts and service for so few vehicles, but the liability was the big killer.

Do you realize Piper has to raise prices on new aircraft to finance liability on the Piper Cubs built back in the 30's, long before applicable standards were laid down? GM did the right thing getting rid of 800 cars.

For all the hype about these great cars being taken away from people who really liked them, the cars were not all that good. They used lead acid batteries and only had a 50-75 mile range, and with no on board recharging plant (they were pure battery electric), they had what I consider to be a fatal flaw, of what amounts to a break down if you exceed the battery capacitiy. If you decided to swing by a super market, or if you got home late and didn't get a full charge, you could run out on the road. Then what could you do? You could not go get a can of gas. It might take an awfully long extention cord to reach a plug in. Likely you would have to be towed. That is expensive. An on board recharging plant makes all the difference.

People liked how quiet they were. They were so clean aerodynamically that there was not even any wind noise at speed. You just heard a bit of tire hum. They were nice cars and a good first effort, but they were not practical.

Although GM killed the EV1, they did not pitch the reasearch and technology developed, and they did not get rid of the people. All this was simply switched to a new effort. They were passed by the parallel hybrids, which Toyota is pushing and I don't like, but they may be about to push ahead with a design I think beats the Prius hands down.

It is all up to the batteries. The car and the other technology is there and GM has designated two suppliers to produce the batteries. If they can come through, there will soon be a car available that I think will be long remembered.

General Motors has not been sitting around with their heads in the sand, they have been working on hydrogen and hydrogen fuel cells. These fuel cells are especially interesting since if they can pull off a practical design, this will have far reaching effects. The biggest managment mistakes I think GM has made has been to give in too easily to union demands, especially for retirement pensions. The system was quite workable with few retirees and a lot of workers, and while GM had lots of money, it was easier than fighting the union and putting up with strikes. Now they are saddled with way too many retirees and too few workers and money is harder to come by. It is costing about $1500 per vehicle today just to cover the pensions. The Japanese do not have these costs and it is a big advantage.

The Competition
The Toyota Prius is so sucessful that it cannot be kept in showrooms. There are people waiting weeks for it. And what do they get? It is a parallel gasoline/electric hybrid. That means it has an ICE (internal combustion engine) and an electric motor operated together to provide the power to drive the car. The output of each goes to a "power splitter", actually a power merger, that then drives the transmission through the differential to the wheels. You basically have a standard car in which the engine has been replaced by an engine - motor pair whose power is combined to act much like a conventional engine would.

In addition to the electric motor, there is a generator on the engine, and a sizeable NiMH battery. The battery is used only as a sort of accumulator, to hold a bit of excess energy until it is needed. The generator replenishes it whenever the engine is producing more than needed. In practice, the engine is running just about all the time, the electrical part simply buffering the output to meet changing demand. This allows a smaller engine running at a more efficient speed.
Really what you have is a gasoline internal combustion vehicle with electric buffering. It does get about 40 mile to the gallon on the highway, and fairly good in city. What it costs is a great deal of extra complexity including more machined parts which mean irreducable expense, wear, and reduced reliability. You have the usual transmission, differential, and ICE. In addition you have a power splitter, which is much like another differential. You also have a large generator, a large motor, and a moderate battery. Note that the NiMH battery cannot have its price reduced much, and its storage is only about 1/4 the advanced lithium ion batteries, but I suppose Toyota could eventually upgrade.

The operation is complicated. There are many indicators on the instrument panel, and you pretty well have to keep the manual in reach to figure out what you are supposed to do. I suppose it can be as much fun as operating an airplane, if you are in the mood for a challenge, but if you just want to drive from here to there, it is not my idea of proper trqansportation.

The Car
Details are still a bit sketchy at present, but this is what I have turned up. The Volt will be under the Chevrolet brand. It is a 4 place plug in serial ICE/electric hybrid. What all this means is that it is basically a pure electric with an on board ICE recharging plant. As such it is simple and straight forward. It has a large advanced lithium ion battery that will hold enough charge for about 40 miles, and can be recharged from a standard 110 volt outlet in about 6.5 hours. As a result, for anyone living within 20 miles of work (78%) and who have access to an outlet (such as a garage), it can be operated indefinitely as a pure electric and not use a drop of fuel.

If there is a need to run some errand or it was not fully charged, no problem. As soon as the battery gets low enough, a 3 cylinder 1.0 liter ICE will start and work on recharging the battery. It has sufficient output to meet the average requiremnents of highway driving, so the car can be driven non-stop until the tank is empty. With a 12 gallon tank and 50 mpg under those conditions, that is 600 miles beyond the 40, a total of 640 miles. If you want to go farther, just stop for gas now and then as you do with a standard car.

Note that the 50 mpg is for highway travel. For a hybrid this is the low one. They are higher in cities because of lower speeds and none of the losses starting and stoping and waiting on lights that cause standard cars to get lower in the city. The Volt may get 60 or more in city driving; it has not been announced.

For diesel, a different engine would be needed because the compression ratio needs to be a good deal higher. For hydrogen, a change to the fuel system and carburation would be needed, but the basic engine would be the same. For ethanol or gasoline, the engine computer could handle any mix with the standard engine.

For someone who has no garage, recharging from an outlet might be a problem, but with 50 mpg in a simple dependable vehicle, people would probably buy it and run it only on fuel. The plug in ability could cut energy costs to maybe 1/4 depending upon gasoline prices, so it would be desireable. Maybe metered plug ins could be provided. Assigned parking at work could allow charging by day instead of by night. An extention cord with one end inside where it could be unplugged, could be ran out to the curb beside your walk, to an all weather outlet.

The car seems to have a single motor, probably a motor/generator as I can't imagine them not using regenerative braking. That would imply a differential and probably CV joints. I would prefer the motor/generators in the drive wheels, but I realize there are engineering problems and it is simpler to go with what you have. A pair of motors, one for each wheel, would remove the need for a differential, and would give positive traction. Maybe some day. In the meantime you are at least getting rid of the transmission. The battery weighs 400 pounds and seems to be mainly in a ridge down the middle of the floor where the exhaust pipe usually runs these days. The ICE is up front, probably with the motor, leaving the trunk available for luggage.

Note that the car is no more complicated than a standard one. You gain two motor/generators and a battery, but get rid of a transmission. Operation would be simpler than a standard. Just turn on the key, select direction, release parking, and drive.

Top speed is 120 mph, which is excessive. I would prefer 80 with a range of 50. There seems to be a need to convince everyone that an electric car is really high performance. I suppose it is a left over perception that they are sluggish. The origional ones were, but that was a century ago. Current electric cars, using better motors and far better batteries, have whatever performance you want to pay for, much as for an ICE.

One of the exciting things about this is getting energy from the grid, which is easy since we have a lot of coal, instead of from fuel, which basically means oil, with all the problems there. Another is the efficiency, and the lower energy costs. Perhaps the most exciting is the possiibilities opened up by hydrogen. GM apparently is very interested in hydrogen. Simply replace the gas tank with something suitable for hydrogen, and probably the fuel line and carburation, and you can run this thing on hydrogen, burning it for fuel. Or, and this would really be great, throw away the recharging plant, both the ICE and motor/generator, and replace it with a hydrogen fuel cell. Now you have an even simpler and probably cheaper car, and it is essentially zero emission, as a hydrogen fuel cell only puts out water and electricity. The hydrogen fuel cell is the easiest of the fuel cells to work, and GM is known to be working on them.

It is all up to the batteries. Many outfits are working on them so I think they are coming, and when they do, this car is going to be a real winner. The cost of the battery will be sky high at first, but should come down soon. Look what is already happening with the big HD TV screens. The first box of floppy disks I bought cost $5 per diskette. The price was down to about 0.25 on the last ones I bought. The car is expected to be introduced at about $20-30,000.