[email protected]· Registered
NiMH batteries are:So it makes you wonder; WHY is GM embroiled in hatching a new battery technology when America needs this car NOW, and lots more models like it. Let's get out of the Lithium quicksand and go build this car.
If it were simply a matter of weight, you would be right, but cost is significantly higher and range significantly lower.Dear Jason,
The question was not which technology holds the most promise; the question is which battery is ready TODAY to go into a production vehicle? What we are talking about here is a 316 lb battery pack vs 175 lbs; 140 lbs is no reason to delay production of any and all electric drivetrains.
Tell that to Lithium Tech Corp., which has been making large format lithium ion batteries for the "military/security, transportation and stationary power markets" for over a dozen years. Their tech was used in the Thunderstruck bike, which holds the world record for 0-60 and 1/4 mile times of any electric vehicle.To date large format lithium batteries are not producable with reasonable yields due to the nanostructure of the plates and the fact that any imperfection will propagate and destroy the cell. That's why Tesla Motors went to production with a battery pack made up of over 6,000 cells. But since they needed the 100+ mile range NiMH was not an attractive option. With a Series Hybrid like the Volt, the big news is that it gets twice the gas mileage of a conventional car and that my friend could cut 150 million gallons per DAY out of the American trade deficit. Driving with zero gas is just a side benefit.
A123 and other Li-Ion battery manufacturers are using a completely different battery chemistry than those used in laptops, for the stated purpose of eliminating thermal runaway conditions. Tesla chose to stick with laptop chemistry batteries, because those are produced in the millions today, so they included thermal management systems and other safety features to eliminate any cascade failures.It is pretty well known that Lithium batteries are prone to explosive self-ignition, but their problems with slow deterioration in both hot and cold temperatures is not as well known. Is GM planning to heat this pack every night of the winter for every car in northern climates? Just normal daytime heat in Florida will cause Li batteries (I believe it's true with all Lithium chemistries) to lose 10 to 20% capacity per year (impedance increases). AC Propulsion is very upfront about that and makes their EBox customers sign a paper stating that they realize that a full battery pack replacement within 5 years is a distinct possibility.
How do you accomodate high cost of NiMH? Having taxpayers provide subsidies? Having automakers accept a loss? Having consumers pay higher prices?The problems you point out with NiMH can all be accomodated, as evidenced by the fact that they are in widespread use in hybrid automobiles. The same cannot be said for Lithium. Case closed.
I've read about lead-acid batteries that use a foam substrate on which to plate a thin layer of lead, reducing weight and increasing surface area of lead on foam matrix to improve overal efficiency, but can't find that website now. I think it may been these guys, but do not know:If you started production of the Volt with NiMH batteries, the Lithium batteries could be made an option when first introduced (assuming that like any embyonic technology, the first production will be low-yield and expensive). Personally I'd like to see a $15,000 version of this car with a 20 mile electric range that uses spiral wound Gel or AGM lead-acid batteries like Odyssey, Optima or Genesis. Then the consumer would really have a choice. Like I said, I recharge my electric car at work, so I only need a 15 mile range to drive 30 miles/day gasoline free.
I agree the Volt is strategic, but not merely for image purposes. The serial hybrid or E-REV configuration is the path to ZEV's, so it positions GM for the future.GM gave itself a bad name with the EV-1 program. It is trying to dig itself out of the hole. If they come out with a new car using the same batteries the EV-1 used, then suddenly people might ask, "Well, why were all the EV-1's crushed if this technology was good after all?"
It's not a face saving argument, it is a fact. Li-Ion batteries are a few times lighter per unit of energy, and several times smaller in volume per unit of energy - that makes an enormous difference. Mostly, though, the breakthrough idea of having a range extender, to reduce the total energy storage needed by 80%, on top of the size / weight reduction of going to Li-Ion from NiMH, is what really makes the Chevy Volt economically feasible.So GM gets out of the problem by being able to tout the new Lithium batteries as the reason why this technology is suddenly viable.
The M in NiMH stands for Lantanum, Cesium, Preseodymium and Neodymium, which are Lanthanide series metals having low to moderate toxicity, so they are certainly not harmless.One last thing.. I don't think NiMh is that toxic. I think you are thinking of Ni-Cad.
I disagree. I'm not saying that Lithium isn't better. What I'm saying is that it was still doable with the previous battery technology. The improvements Lithium provides are not an order of magnitude better. And the argument of the range extender doesn't work with me, because GM had a prototype EV-1 that had a range-extender back in the 1990's. So again, this isn't a new idea. If they claim the batteries were too expensive, then they could have easily scaled back the NiMh packs on the EV-1 to a 40-mile (or heck, even a 20 mile) all-electric range, and relied on the range extender for the rest of it.It's not a face saving argument, it is a fact. Li-Ion batteries are a few times lighter per unit of energy, and several times smaller in volume per unit of energy - that makes an enormous difference. Mostly, though, the breakthrough idea of having a range extender, to reduce the total energy storage needed by 80%, on top of the size / weight reduction of going to Li-Ion from NiMH, is what really makes the Chevy Volt economically feasible.
I still believe that GM knows they screwed up with the EV-1 program, and now they are trying to save face by touting new technology. Yes - the technology for the Volt is undoubtably better, but not a "dealbreaker" better. In other words what they had before was just as viable.
The only difference now is the rising cost of gasoline has made their large Hummers, Suburbans, and Tahoes unattractive and hard to sell. They are feeling the financial pain of their previous strategy. Now they realize they need to diversify their products if they plan to survive well into the 21st century. Now they are sitting there thinking "If only we had mass produced the EV-1, we'd be selling hundreds of thousands of them now with such high gas prices."
Actually. I was unaware that GM admitted to screwing up. This is news to me. Can you point me to some website or video so that I can see exactly what he said? This is interesting, as I was still under the impression that GM had not admitted to anything.Adric22
Bob Lutz did a much better job pointing out that GM screwed up back then, in his remarks at the auto show. He knows it. We know it. Get over it.
At the show, Bob went over the difference between being a car company "with the family name on the building" (read Toyota) and one that is beholden to it's stockholders. When Toyota says "I'd like to sell a hybrid" and the engineers say, but you'll lose money, Toyota can still build it. When GM knew that it'd take 2-300 million to develop a hybrid AND lose hundreds of millions the first few years, Bob said, "Who wants to be the one to present THAT to the board". Maybe someone here knows of a video clip of that part of his presentation, but I know he said it. I was there. He also said that if he had to present the same situation now, the board would tell him to go forward with it.Actually. I was unaware that GM admitted to screwing up. This is news to me. Can you point me to some website or video so that I can see exactly what he said? This is interesting, as I was still under the impression that GM had not admitted to anything.
See this post on the GM-Volt website, link attached.Actually. I was unaware that GM admitted to screwing up. This is news to me. Can you point me to some website or video so that I can see exactly what he said? This is interesting, as I was still under the impression that GM had not admitted to anything.