You better be sitting down for this!!!!!!!!!!!!!!!!1

I've been watching EEStor for a while - GEM has a lock on the first systems for automotive use. There's much debate on whether they can pull this off. They're supposed to deliver by end of this year (BTW, FOX is about one year behind on this story...)

Check out: this thread which started back in January 2006.

I hope they come through. They say they could produce a 50kWh system for around $2000 in quantity. That would certainly revolutionize the EV world. Keep your fingers crossed but don't count on it yet...

John H.
Blue XM-2000
Ann Arbor, MI

About that thread you linked to I just have to comment on the topic post.

Because it's a solid state battery rather than a chemical battery, such being the case for lithium ion technology, there would be no overheating and thus safety concerns with using it in a vehicle.

I don't know how you can make either conclusion. Capacitors heat up too. The resistance limits the peak power of a capacitor just as it does in a battery. And as for safety concerns we don't have enough information to establish just about anything at this point. 52 kwhrs is a lot of energy, and there's also a lot of potential energy stored in dinamite and gasoline which is why they can explode.

None of these claims except construction and cost are significantly better than other ultracapacitors. Although they sometimes refer to the technology as a battery, it is clearly an ultracapacitor.

Lets compare to an ultracapacitor. Take this one here with a specific energy listed as 4.5 wh/kg.

Compare that to EEStore's 52 kwhr 400 lb pack. Thats 181.8 kg. 52000/181.8 = 286 wh/kg. Seems significant to me.

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Avatar taken from http://www.electricmotorbike.org/
My KZ750 Project: here

Hi,

As with all posts on all boards one has to decide which are the knowledgeable posters and which aren't.

In your first quote I think he's likely referring to the thermal runaway characteristics of certain chemistries (namely the LiPo batteries everyone likes to quote that "blow up"). Before using any power source in a commercially produced passenger EV there is a specific NTSA (sp?) test designed for electric vehicles - search the http://www.teslamotors.com site for specifics.

In your second quote whether it's an ultracapacitor or a battery is really immaterial - what is germane for our interests is that it claims to be an "energy storage device" that can store 52kWh in a small, light package and deliver that power in a suitable fashion to power an EV.

I'm hoping that they can engineer much smaller packages for a much smaller price. Imagine 5.2kWh on your ebike for only $200... :jawdrop:

John H.
Blue XM-2000
Ann Arbor, MI

A capacitor is .. at its simplest .. two metal plates hooked to a circuit, with an insulator between them. They conduct and store electricity even there is no circuit between the plates. The better the insulation between them, the more energy can be stored in the capacitor.

In the late 90's I read a breathless article gushing about the newly discovered ultracapacitors. The article said they were dependent on a special kind of gel which scientists had developed that they could fill with zillions of tiny bubbles, all of which dramatically increased the capacity of the capacitor.

I don't remember why barium titanate can also work in a battery. Batteries work on a different principle than capacitors. It has something to do with storing chemical energy as bonds in some kind of chemical equation and then releasing it as electricity.

- David Herron, http://davidherron.com/

Barium Titanate offers high-K. The higher the K (capacitor plate insulating properties) the better the storage. Had to learn that for eGrav. ;)

http://my.execpc.com/~endlr/ceramic.html

I'm no expert but I'm guessing a better insulator helps up the voltage.

Estored = 1/2 * C * V ^ 2.

What ultracapacitors seem to do is increase the capacitance by increasing the surface are by using carbon. From the wikipedia ultracapacitor article:

The first supercapacitor based on a double layer mechanism was developed in 1957 by General Electric using a porous carbon electrode[1]. It was believed that the energy was stored in the carbon pores and it exhibited "exceptionally high capacitance",...

And more recently it seems they are using carbon nanotubes to increase the capacitance. As you can see from the above equation, you can store a lot more energy if you increase the voltage, and this may be what EEStore is doing though I haven't read up on it.

Hypothetically, all things being equal with the ultracapacitor I posted (which they certainly are not but for discussion purposes) than to get a 63.6x increase in energy you'd need to increase the voltage from 2.7v to 21.53v.

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Avatar taken from http://www.electricmotorbike.org/
My KZ750 Project: here

Are you sure Altairnano are using barium titanate in their batteries?

If you want to know more about the EEStor device I suggest reading this thread (same as before) and concentrating on the entries by CapacitorMan. He's a detractor of the technology but he certainly seems to know his stuff and there are at least a couple of longer posts that describe the issues in some detail.

As I posted on that blog - I sure hope EEStor comes through but I wouldn't give it more than a 1 in 10 chance of living up to the hype. I sure hope I'm wrong!

John H.
Blue XM-2000
Ann Arbor, MI