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[BrianTRice@gmail.com]

Ars Technica has an interesting article up called "Batteries: What’s here versus what we need" which gives a big picture overview of battery technology and how it's developing economically.

One interesting point for vehicles was this paragraph:

For a midsized vehicle to cover a range similar to existing vehicles (about 300 miles), you need about 100kW·h of battery. That's possible with lithium, Mathias said, but it adds a lot of weight to the car. Then there's refueling. Gas can be put back into a car at a rate of about 150 miles of travel per minute; the equivalent value for hydrogen is 100 miles per minute. Even with a supercharger, the figure for batteries is about six.

They make the case that, before a projected new generation of battery density becomes economical in say 5 years, that fuel cells (described as electric propulsion with an onboard generator) will be the best strategy for long distance travel.


Motorcycle designs may be able to get ahead of that by a streamlined design with fast charging. Anyway, that's my hope.

[NoiseBoy]

Im pretty sure the problem with battery technology is funding.  DoE hands out small grants in the tens of millions each year but finding the Higgs Boson cost something like $13 billion USD. For something which as far as I can tell does nothing but massage the ego's of physicists.  Put that kind of funding into an international effort to improve battery tech and you will have your five times energy density in a few years no problem at all.  Tiny companies and universities are getting close, they just need the money to push it through to production.  The benefits for society are enormous, far higher than theoretical physics anyway.

[Richard230]

I am waiting for someone to announce the new Higgs Boson battery.   

[protomech]

It's technically possible to build battery packs that can accept very high charge rates. Tesla has done this with the Model S pack (1.3C - 2C), but it's certainly possible to do this with a smaller battery pack as well. I fully expect the ~50 kWh Model E pack to be able to accept the fully 135 kW charge rate (2.5 - 3C).

The other point they miss is that miles per minute is a terrible metric for the same reason miles per gallon is a terrible metric.

Going from 20 mpg to 30 mpg is a greater reduction in fuel consumption than going from 30 mpg to 50 mpg.

Likewise, 6 miles per minute sounds much, much worse than 150 miles per minute. And it is, the gas fill rate is much much faster. But you save more time going from 6 miles/min to 12 miles/min than from 12 miles/min to 150 miles/min.


Look at it another way:

Assume a 70 mile trip @ 70 mph.
Add 5 minutes to each trip to account for pulling off the highway, plugging in, etc.

Gas scenario:
60 minutes of driving. 5 minutes to pull over. 0.5 minutes to refuel. 65.5 minutes total.

EV scenario:
60 minutes of driving. 5 minutes to pull over. 12 minutes to refuel. 77 minutes total.

The EV scenario is "only" 17% longer, even though gas is 30x faster to fill.


And in practice, since usually the EV will start full from an overnight trip, shorter trips will look like this:

Gas scenario:
120 minutes to drive 140 miles. 5 minutes to pull over. 5 minutes to fill up, pay your $15, etc. 130 minutes total.

EV scenario:
120 minutes to drive 140 miles. 10 seconds to unplug at the start and replug at the destination.

[Richard230]

Here is another interesting and informative article regarding the possibilities of future battery designs:

http://www.nature.com/news/the-rechargeable-revolution-a-better-battery-1.14815?utm_source=Argonne+Today&utm_campaign=bcc4e4b73e-AT+03%2F08%2F14&utm_medium=email&utm_term=0_d2beb44dd5-bcc4e4b73e-236990293

[BrianTRice@gmail.com]

Thanks for the interesting replies.