I just received a link from a reader in Germany about a company that is proposing a range extender battery pack. As long as the pack will be available for rent on an as needed basis, it's a clever way to overcome the economic problem. The site is all in German, but pictures have no language barriers:

www.stromcar.de

I have been following this with interest. I like the new Chevy volt, even though it is not a true electric car. Thanks

You obviously don't know anything about Electric cars, so why are you pretending to know??

GM tried to suppress NiMH batteries by using defective Delco lead-acid batteries; when it upgraded to non-defective PSB 1260 lead-acid batteries the EV1 ran fine and had over 100 miles range.

This had nothing to do with the advent of NiMH batteries, which GM had controlled since 1994 and which GM was refusing to use. It was Toyota which brought out a NiMH RAV4-EV and supplied the NiMH batteries fro the HondaEV and RangerEV, without Toyota you never would have heard of NiMH.

CARB forced GM to release the NiMH EV1 in Dec., 1999; but GM only let them live for 3 year leases, then crushed them.

The EV1 had no problems except GM sabotaged and then crushed it.

Study and learn before you write falsehoods.

There are at least two flaws with this argument. The first is the assumption that battery costs will remain high; it's like arguing against the adoption of electric light because the first light bulbs were very expensive. The second is that your own numbers show breakeven for 100 miles range at $3.46 per gallon. Gas prices in the US recently exceeded that and will do so again, eventually permanently.

Wilbur Force is right. Battery cost will go down (especially if the long-rumored, potentially vaporware EESTOR ultracapacitor ever sees the light of day), and it is a very good bet that the price of petro-fuel will go up. Also, the analysis here only looks at the breakeven point with respect to fuel. EVs are generally more reliable and can provide better performance than internal combustion engine vehicles. If the battery pack costs a little more to get to a 100-200 mile autonomy, that additional cost may easily be mitigated in the consumer's mind by the car's zippy performance, or the fact that it will never need tune-ups, oil-changes, or smog certification, just to mention a few recurring expenses of conventional cars. The number of major repair incidents and costs should likewise be reduced, as there is a lot less to go wrong with the electric motor, transmission, etc.

What is needed is a total cost of ownership analysis, which should increasingly favor EVs as energy storage technology improves and becomes less expensive.

wilbur force,

Who wants a BEV with only 100 miles range? To be practical, it should have a 250 mile range, with rapid recharge batteries, which would be even more expensive. Now you are talking about gasoline prices closer to $10 per gallon before you see any cost benefit.

What I'm surprised about in this discussion is that no one (including John) is considering the very real possibility of $10 gas.

As far as I'm concerned, that's the main flaw in the argument. I expect we'll see $10 gas before we see a 2x imporvement in battery technology. As the last commenter noted, this would make even EV-250s economic (although still very expensive.)

The era of 3 cars per houshold will end with the age of oil. Get used to it.

John left out a crucial key point in his argument, which is that these batteries are CONSUMABLE. The batteries in the Tesla Roadster, for example, are rated for about 500 full charge-discharge cycles, before requiring replacement. (The lithium is recycled, but you still need to buy a new battery pack.) Given a real-world range of 200 miles per charge, that gives a total range of 100,000 miles per pack.

If the range were reduced to 100 miles, the batteries would need replacement twice as often, completely negating John's financial argument. Furthermore, the maximum power output drops by half, since at full throttle the Roadster uses most of the power the battery pack can supply. (Correct me if I'm wrong.)

In any case, lithium-ion batteries are "happiest" when maintained between about 25% and 75% charge, and the pack could withstand 1000 charging cycles in this limited range, if not many more. So buying a 200-mile pack and staying near 50% charge (with occasional excursions to 95% and 5%) is actually more cost effective than having a 100-mile pack that gets fully charged and discharged each time, requiring replacement after less than half the distance.

As technology improves, I look forward to replacing the pack in my Roadster with a 400-mile pack in a few years. :)

There is another fundamental flaw with this argument. It assumes that batteries will be the fuel of the electric vehicle. There are companies out there that have developed fuel cells that will dramatically increase the range of the EV while reducing the total cost of ownership.

Wilson- Fuel Cell EVs are simply a variation on Range Extended EVs which use an IC engine to charge the battery. A fuel cell, like the IC engine in an REEV, allows a high energy density liquid fuel to supplement the batteries.

This is the crux of Shai Agassi's solution. Take the battery schtick out of the current equation and get the EV's out on the road with a separate battery technology TBD...

Batteries cost $500/KWh. Therefore, batteries will always cost $500/KWh. This seems to be the argument made in the article.

Batteries for cell phones and laptops get cheaper and 8 percent better every year. (a mini-Moore's law) That needs to built into any analysis of the trends.

Also tax rebates for home Solar make the fuel costs drop for some.

There are also two type of battery chemistries in your table. The low-range many-charge versions like in the Volt and the other few-charge long-range batteries in the Tesla. Completely different kinds of apples.

Interestingly, the $3.46 number was right on though. Many economists noted that when gasoline prices rose last year that it was at the $3.50 mark when everything changed. Auto sales dropped and driving went down because that was the point where consumers shifted their thinking.

A revisit of that price is a perfect scenario for the hero EV to step in and save the day.

So the question may be, "How long do you think gasoline will stay below $3.50?"

With due respect the short life cycle of the LABs was a big problem with the Gen1 vehicles. That's why they couldn't meet the CARB standards.

I truly appreciate the other comments, but think most of you have missed the key point that the amount of battery power you put into an EV increases as the range increases and while the cost of electricity may be low, the cost of amortizing excess battery capacity will screw up the economics every time. As long as battery and daily travel distance are closely matched, the numbers work well. As soon as you buy a 100 mile range on an EV that you plan to drive 40 miles a day and the economics are shot regardless of what batteries and gas cost.

I would also suggest that anybody who believes battery costs will plummet in price like electronics did is living in a fools paradise. Moore's law does not apply to chemistry and never will. As long as more than 70% of battery costs are attributable to commodities that are used as raw materials, price will tend to follow commodity prices.

I've heard all the blogger hype on EEstor and will remain unimpressed until they introduce a product and attach a price tag to that product. The same goes for fuel cells and all of the other future tech that looks promising but is not currently available.

We have urgent energy storage needs today and we need to go to work on them today. For that we have to work with the toolbox we have. When new tools become available, we need to be ready to adopt them if they make sense.

As soon as you buy a 100 mile range on an EV that you plan to drive 40 miles a day and the economics are shot regardless of what batteries and gas cost.

No. You are actually better off not using the entire range of the battery, because it puts less wear and tear on the battery chemistry.

To charge a 100-mile battery from 30% to 70% (and then driving 40 miles until the charge is 30%) uses the same amount of electricity as charging a 40-mile battery from 0% to 100%, and gets you the same distance, but it is much easier on the battery (with current Li-ion chemistry). The 100-mile battery will last at least 2 1/2 times longer because it is going through many fewer cycles. (Charging from 30% to 70% and discharging back to 30% counts as 0.4 of a cycle.)

Also, the 100-mile battery can be driven until it only has ~40% of its original capacity left (perhaps 10 years), and will still give a practical 40-mile range, whereas the 40-mile battery will start giving sub-40-mile range within a year or two of purchase. If you truly need a 40-mile range, the 40-mile battery will need swapping after only a year or two, negating the up-front savings.

In a nutshell, a high-range battery with 50% reduced capacity is still a useful medium-range battery. But a medium-range battery with 50% reduced capacity is practically useless. So the medium-range battery will need replacement far more often, defeating the purpose of "economizing" that way.

Ben, I think there is a sound basis for your suggestion that using less than 100% of the battery capacity is probably the best way to maximize battery life, but it's important to remember that every kWh of battery storage you buy makes the cost - benefit equation less attractive.

My assumptions for the article were very gentle. I did not question the widely held belief that the Li-ion producers would be able to reduce their product costs from $1,300 per kWh to $500 per kWh. I also did not question the travel range and life cycle assumptions that people are so fond of. When you start making reasonable adjustments to the cherished assumptions, the cost-benefit equation goes from bad to horrible.

"I would also suggest that anybody who believes battery costs will plummet in price like electronics did is living in a fools paradise."

Actually, they live in reality. 8%/yr is the rate of improvement in current battery tech. This is a big reason why ipods and laptops get smaller and more powerful. 8% means doubling every 9 years. Sure, 8% isn't the 35%/yr of moore's law, but it's a far greater rate of improvement than ICEs have seen in recent decades.

Furthermore there's a "punctuated equilibrium" effect where large but unpredictable leaps are made in storage technology; for example, Stanford's nanowire battery:
http://news-service.stanford.edu/news/2008/january9/nanowire-010908.html

Several people have referenced an 8%/yr rate of improvement in battery technology. What does this mean? Lowering the cost/kWh? The kWh/kg? Rate of recharge? What is a definitive reference for this "law"?