Is General Motors Backing Off Of The Chevrolet Volt Type Plug-In Hybrid?

by Jack Lifton on August 7, 2009

in Hybrids & EVs, News Analysis

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Although you would think that the writers of Popular Mechanics (PM) would be familiar with the various types of hybrid power trains now in actual use, or in the planning stage, it is obvious from the PM article on the proposed Buick “hybrid’ that the magazine’s writers, fact checkers, and editors do not understand very much about such things at all. Or is it me?

PM has decided that a new model Buick “hybrid” is an extension of the Chevrolet Volt plug-in hybrid electric vehicle (PHEV). Those of you with a memory for BS will remember that the Chevrolet Volt power train went from originally being called a PHEV – the description of which is supposed to be of a battery-only powered electric vehicle, that can only be recharged by being plugged in to (supposedly) an ordinary household outlet (110VAC, single phase) – to finally being called an extended range PHEV. The latter will carry a small internal combustion engine, the purpose of which is NOT to directly power the car through a coupling to the driveshaft or to generate electricity to directly power an electric motor coupled to (or being) the driveshaft, but only to maintain the level of charge in the onboard battery, at a sufficient level to allow it to be driven to a charging point. Got that!

PM’s writer either didn’t understand the GM hypesters or perhaps understood them only too well. He says that (All italics below are mine):

The plug-in hybrid version [of the Buick] has the potential to increase fuel economy significantly. A 3.6-liter gas engine with direct fuel injection and variable valve timing coupled to an electric motor powers the front wheels of the new vehicle. The lithium ion battery pack will use the same manganese-spine based chemistry as the Volt’s battery pack. Like the Volt’s battery, the Buick’s will be built by LG Chem. The Buick’s battery, however, will have only 8 kwh of capacity, about half of the Volt’s. The battery resides under the rear cargo floor. Using a 110-volt household outlet, the Buick’s battery can be charged in four to five hours. GM says that in early tests, the Buick plug-in travels more than 10 low-speed miles on electric-only propulsion. Critical details like fuel economy and how much all this will cost have not been released.

Let’s look at this engineering-ignorant discussion in detail:

1The PM article says that “A 3.6-liter gas engine with direct fuel injection and variable valve timing coupled to an electric motor powers the front wheels of the new vehicle.” I suspect that the fair size (3.6 liter is 3600 cc) gasoline engine is directly coupled to the drive shaft -which may well also be the rotor of an electric motor, in part – and is the car’s principal source of propulsive power, as it is in the Saturn Vue two-mode hybrid upon which it is supposedly based. I believe that the two-mode hybrid is NOT a PHEV (It can operate with a dead battery!); the Chevrolet Volt IS an EV (it cannot operate with a dead battery).  The Volt, is propelled only by an electric motor!

I further suspect that the Buick’s gasoline engine will also power a generator to keep the battery’s charge level high enough to avoid damage to the battery from attempting to use it when its charge is at too low a level. The small 8kWh battery will be of very limited use, and used on its own, may propel the car for 10 miles, but I think this would be at less than 15 mph. This would be of use only when you:

  1. ran out of gas, or
  2. the “gas” engine failed, and
  3. you happened to have a charged battery, and were within a few miles of a charging point or, better yet, a gas station. I understand,of course, that the electric motor is to reduce fuel usage and emissions during a cold start and when starting from a stop or an idle.

2manganese-spine“: I don’t know what a “manganese-spine” might be. It might be part of the equipment used to rebuild Steve Austin, the Six Million Dollar Man. I do know what a manganese-spinel is, and I do know that “LG, which is the third largest producer of lithium ion batteries, uses the lithium manganese spinel for its cathode.”

Let me conclude by pointing out that not only Popular Mechanics, but also General Motor’s public relations department, should be ashamed that PM managed to not only misunderstand a press release and a press conference, but also managed to get their ridiculous error-ridden commentary into print and on the Internet without anyone at GM noticing it.

Buick might be better off putting the battery in the trunk, connected to nothing at all, so that PM could claim the car was “equipped with a battery.”

GM is unable now- it is too late in the game – to get a supply of nickel metal hydride batteries and produce a Prius, Insight, Fusion full hybrid “fighter,”. It now resorts to trying to confuse the buying public into thinking it has some “advanced” propulsion system in a Buick “hybrid” model, which does not have the range or the power of the full hybrids of its competitors, and I’ll bet it doesn’t do too well on total emisisons either with such a small battery and such a large engine.

One thing that PM got right in the otherwise poorly written and researched article: The Buick hybrid proves that “ [t]oday’s announcement reveals that GM is looking beyond the Volt.”

This is because the Volt is not a very good idea in the first place.

The next advance at GM could be to a lead-carbon-acid battery utilizing full hybrid available with a gas or diesel engine. I can’t imagine what PM would think of that, because it being a very good idea, it would most likely be beyond their understanding.

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