Detroit — It’s difficult to think about the future when today seems so dire.
Faced with the incredible tsunami of red ink and corporate ineptitude that is the General Motors we read about every day, it’s hard to contemplate that sometime — hopefully in the not-too-distant future — the world’s once-largest automaker will again be judged on the vehicles it builds.
Indeed, if GM is to come out of this morass of bad debt and even worse public relations, it needs a raison d’etre — a signature model or technology — that lets consumers know the General is back in business and ready to compete head to head with the best in the world. That car is the Chevrolet Volt.
For those who don’t know, the Volt — also known as The Car That Will Save General Motors — like the common hybrid, has an electric motor and a gasoline engine. However, unlike hybrids, which use both the gas engine and electric motor to power the wheels, the Volt is driven only by electricity.
Its onboard 1.4-litre four-cylinder engine acts only as a generator to power the electric motor once the 16 kWh lithium ion battery has been depleted.
To distinguish it from the lesser hybrid species, GM calls it an extended-range electric vehicle. Indeed, the Volt is essentially an electric car, but with the capacity to keep on driving once the electrons have stopped migrating between anode and cathode. Though its 64-kilometre range on electricity alone is less than the 160 km claimed for the Nissan EV, the Volt can continue driving as long as you’re willing to supply it with gasoline.
Crucially, it all works as advertised. In a short drive around GM’s Technical Center in suburban Detroit, the Volt proved every bit as sophisticated — if not more so — than the Nissan EV tested the day before.
There’s plenty of power — Chevrolet claims a time of nine seconds to get to 100 kilometres an hour, thanks to healthy 111-kilowatt electric motor. From a stop, the Chevy Cruze-based prototype (GM will start building pre-production Volts in about a month) takes off with a healthy lunge, the low-end torque characteristic of an electric motor about equivalent to a mid-sized V6. Things taper off above 100 km/h, but performance will not be an issue for even the first Volts.
Neither will civility as the Volt feels at least as sophisticated as the aforementioned Nissan. Its power delivery is equally linear and there’s the same lack of hiccups and odd power surges that characterizes lesser electric vehicles. And, if anything, the Volt is even quieter than the already impressively silent Nissan, the lack of noise from the motor in total contrast to the racket that emanates from most gas engines. In fact, Jon Lauckner, GM’s vice-president of global program management, says one of the major challenges going forward is making sure the rest of the Volt is as quiet, since the lack of drivetrain noise will highlight any disturbance coming from other sources such as tires, wind or body.
A peccadillo of most other electric cars — the artificial feel caused by regenerative braking (the energy from stopping is used to recharge the batteries) — has been completely eliminated in the Volt. In many EVs, applying the brakes results in an abrupt transition from cruising to slowing down. In some cases, even letting off the gas feels like throwing out a boat anchor. In the Volt, normal operation sees a minimum amount of regenerative braking so that the car appears completely conventional. But, says Lauckner, pull the gear shift knob into the traditional “low” position and there’s noticeably more retardation (and therefore more recharging) when letting off the gas. That’s the polarity of the electric motor being reversed so it can recharge the battery.
One misconception surrounding the Volt’s operation must be cleared up: The gas engine does not actually recharge the batteries. Instead, it is connected directly to the electric motor and simply acts as a generator, providing the powertrain with electrical energy. Once the lithium ion battery is depleted to about 30% of rated capacity, it stays there until recharged using an electrical outlet. It’s worth noting that even though GM never lets the car’s batteries get depleted below the 30% mark or charged beyond 80% capacity (the deeper a battery cycles, the quicker it wears out), that’s still a far wider range than allowed in current hybrids. Despite the wider range, GM claims the batteries will last a minimum of 10 years or 240,000 km without replacement. The company also says that driving a Volt on electrical power for 18,000 km a year consumes about the same amount of electrical energy as a water heater — and at about the same cost.
In the end, those energy savings will be part of the attraction for the Volt. In the ultimate of ironies, it is now General Motors hoping for higher gas prices to make its new signature technology more attractive to consumers.
Politicians, pundits and consumers alike have been looking for the reason to save GM. The Chevrolet Volt is it.
Mass-produced miracle battery still years away
One of the reasons for the controversy regarding the supply of lithium has to do with the different estimates regarding how much is actually needed to power an electric car. Although they are lumped into one category, hybrid electric vehicles (HEVs) and electric cars are two different beasts with different needs. Even the conversion of a conventional hybrid to a plug-in hybrid electric vehicle (PHEV) is problematic.
In the simplest terms, the demands on batteries in current hybrids are tightly restrained. Unlike the batteries in a flashlight, which run until they are thoroughly depleted, the cells in a hybrid vehicle — whether nickel metal hydride or lithium ion — operate in a very narrow range. To promote extended battery life, automakers may engineer them to use as little of 10% of their rated power before demanding they be recharged either by regenerative braking or by the gasoline engine. That’s why a conventional hybrid’s range of electric power alone is minuscule despite the most frugal driving behaviour. It’s also why engineering a plug-in hybrid involves more than adding a wall socket.
The goal of the plug-in is to allow a longer electric-only range and minimize operation of the gasoline portion of the drivetrain. To accomplish this, the existing batteries have to operate through a far greater range of energy dissipation — i.e., allowing their energy levels to reach as low as 30% of reserves. Experts contend these deeper discharge rates will reduce battery life from an expected eight years to just three. The other alternative is to bump up the battery’s size, increasing lithium usage.
Although there are numerous alternative battery technologies being tested, the study of electrons is a relatively mature science. While computer advancements still manage to follow Moore’s Law, which states that the number of integrated transistors per integrated circuit (a measure of computing power) would double every two years, battery performance seems to improve at a much more modest pace. Despite many claims of huge nanotechnology developments, the mass production of a miracle battery may still be some distance in the future.
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