Tuesday, August 5, 2008

New Tyler Hamilton Article on EEStor Inc.

Tyler Hamilton has released a new article on EEStor Inc including several insights from Dick Weir on Technology Review, published by MIT. I want to focus in on a key excerpt concerning EEStor's status with regard to production expansion and information flow:

Weir says that momentum is building and that he'll start coming out with information about the company's progress on a "more rapid basis." Plans are also under way for a major expansion of EEStor's production lines. "There's nothing complex in this," he says, pointing to his past engineering days at IBM. "It's nowhere near the complexity of disk-drive fabrication."


Dwight said...

There's also this:

Weir 'says that the company is working toward commercial production "as soon as possible in 2009," although when asked, he gave no specific date. "I'm not going to make claims on when we're going to get product out there. That's between me and the customer. I don't want to tell the industry."'

OntarioInvestor said...
This comment has been removed by the author.
OntarioInvestor said...


stephen_b said...

New article at MIT Technology review.


stampergl said...

Ouch, my comment appears to have been censored by B. Please know I did not intend to be offensive towards Mr. Hamilton. I wish that the line I questioned in his article had been phrased as a direct quote from Mr. Weir. I do think it is unusual to be talking about large expansions in a production line that has not yet produced the product successfully. That said, the world surely needs such a breakthrough, and I hope my skepticism is unfounded.

mrjerry said...

See any connections...

EEstor in talks with solar company for exclusive agreement..
July 2008 Miasolé Solar "company was rumored to be raising an additional $200M.[9]"


Kleiner Perkins VC, Prodution plans 2009.

"The company is also in serious talks with potential partners in the solar and wind industry, where EEStor's technology can, according to Weir, help put 45 percent more energy into the grid. He says that the company is working toward commercial production "as soon as possible in 2009," although when asked, he gave no specific date. "

Alex said...

Wasn't EEStor supposed to deliver units to Zenn at the end of 2008? I guess we are to infer that the delivery schedule is slipping again? 2g Li-Ion's will be on the market in 2009. Zenn's stock will suffer considerably if EEStore does not deliver.

richterm said...

Good point alex. I think Zenn has to respond to this since they've been telling their stockholders they're expecting delivery in 2008. The "late 2009" debut of the CityZenn would be almost impossible IMO if they don't get the EESUs this year.

Lensman said...

Yes, this is another delay. The third? I can't say I'm surprised. I followed the development of the Tesla Roadster, and there were/ are similar delays. Setting up a production line for new, bleeding-edge technology is very difficult and often has unforeseen problems and delays.

I can only assume that the result off the first production line was not satisfactory, or EEstor wouldn't be revamping their procedures and announcing yet another delay.

At least, that's the optimistic scenario. The pessimistic one is they've realized their technology simply won't work, and are now just trying to stretch out the inevitable collapse of the company as long as possible.

richterm said...

Eestor's story for delay was that basically they needed to be able to meet Lockheed's more stringent specs (that's the implication I got). That makes sense, but I'm sure Zenn would rather have kept to the schedule. I suppose there's nothing Zenn can do in redard to pushing the timeline other then screaming and yelling.

nekote said...
This comment has been removed by the author.
ricinro said...

Your pessimistic scenario suggests that eestor and those in the know are in the bad religion death spiral. Where they know something to be un-true yet they can't accept it. I would expect the principles in a corner rocking back and forth muttering to themselves with this level of stress. This doesn't appear to be the case. Richard Weir appears to be driven and busy. His recent comments are all focused on production lines and the expansion of these lines for expanding applications.
This seems like full steam ahead and damn the torpedoes engineering (been there done that).

Satya51 said...

You guys maybe antsy, but these announcements must be driving Maxwell, their SME's, and potential customers nuts.

It is important to understand that the production line is for components. Components go into various engineering designed packaging for different uses.

Then there is the electronics, and contracts for raw materials. 2009 a delay! What, do you think that completed ESU's jump out like Athena?

I don't read anything new about delivery in this announcement and am sticking to my guess of September for permittivity. Then comes serious GM, Ford negotiations. Toyota maybe but they don't have a serial hybrid.

Wind mills will have large stationary units and packaging won't be that difficult. I wonder if the orders come first, then the lines are built for order size?

Question is how long to build a line? What a business to run, R. Weir is going to have to get a management team put together (Mort Topfer can help there). Perhaps Dell will lend a hand on the production?

richterm said...

I'm antsy, but optimistic. Again, even if it's understandable, it's still a delay. ZMC made a big show of saying th CityZenn would be available in 4Q09. If nothing else these statements by Mr. Weir shed doubt on that communication ZMC had with its stockholders.

ZMC should try to address the concerns that they're being naive. They don't have to break any NDAs to do that - just confirm that they're aware of the technical discussions going on and that they're comfortable based on the explainations they have been privy to. If they just said that it would probably boost their stock a point or two right now. I know I'd buy more.

ricinro said...

I also thought that the recent press release was to meet military specifications. The tradeoff was time with the payoff being a robust production line for better yield and future expansion. Zenn would be much better off with an excellent EESU rather than a ok EESU in the long run.
Making good processes and line is much harder than hoped (in my experience). Delays in this process are indictative of incremental success and not likely failure.

richterm said...


I don't disagree with that. I just think Zenn went out on a limb with promising 4Q09, and now that limb is cracking. They kind of made jaws drop with that announcement. They could have just as easily promised 4Q10 and everybody would have been impressed too. but not thye've promised, and that affects stockholders - hopefully only for the short term, but it still affects them. Underpromise and overdeliver.

Marc said...

Richard Weir runs a Private company. Granted any shareholder of publicly held Zenn would like to know everything they can of the status of EEStor but in reality and logic Weir needs to say nothing publicly as he owes none of us anything. It is Zenn that owes us information and what come out of Zenn is dependent on where Ian would like to see the share price to be

I am ever more of the opinion that Weir is not running a scam or anything close to one. He has nothing to gain and if this was a scam he would be talking out of the side of his mouth and not directly out the front. My major concern is that he sounds like a very focused and strict perfectionist and therefore my drag his R&D out to the point where we lose the "edge". I hope somebody is whispering in his ear lets get it in production and like Apple we can come out with a new and improved version every six months but Lets Beat the Competition. If nobody is whispering this in his ear I hope somebody who has his ear and reads this blog will start whispering these sweet nothings.

Thanks for your ear Marc

Marcus said...

marc, richterm doesn't seem to be suggesting EEStor do anything. It is Ian Clifford that could easily help his own public company by doing as richterm suggests.

zawy said...

"they recently got an ultracapacitor order from McDonald Douglass for a military aircraft."
Say wha?

stephen_b said...

All of these alleged exclusive deals are starting to leave a bad taste in my mouth, since it really skews the market. Take solar. An exclusive deal with Miasolé would wipe out the other players, which would be bad for everyone.

I hope that all players in the solar and wind market will have equal access to EEStor's tech.


EEStor Fan said...

When I hear that EEStor has gotten validation of their technology from a few independent, reputable organizations like Argonne Labs, THEN I will start to get VERY excited indeed.

All the lithium ion battery technologies going into the Chevy Volt was validated for all sorts of factors. EEStor needs to get that kind of "seal of approval" from the scientific community. Once it does, you can bet that EEStor will become a sensation. You'll be hearing about EEStor on CNBC, Fox Business, and CNN all the time. They'll be a VERY popular company that the whole world will respect.

Big Oil executives and OPEC however, won't be happy campers. As they freak out, the rest of humanity will rejoice. EEStor could take away their "gravy train" in a BIG way.

I'm sure OPEC and "Big Oil" would love to "strangle the EEStor baby" or "cut off their air supply" before it is born. Bury the invention in the basement and all that. Too late! Once the scientific community validates the EEStor technology, "the cat is out of the bag". This EEStor technology really could be "a genie in a bottle" that totally changes the world.

EEStor technology could be HUGE in the solar and wind industry, the electric utility industry and the auto industry.

God, I hope that EEStor can really "deliver the goods" with this technology. I can't wait to see the first Zenn cars with EEStor batteries driving around. It might be like that "IT" thing with Dean Kamen once it comes out. The difference is, it's not a scooter but a genuine, world changing energy storage product that WILL change the world in a lot of ways. Positive ways.

Mother Nature will be very pleased with the people at EEStor. It could help out the environment bigtime and save people money on their transportation and energy bills all over the world. Those "poor souls" in the oil industry will have to go back to using their oil for plastics and pharaceuticals. No more record breaking multi-billion dollar profits for them. Yeaaa ...

Like the mexican bandit says in the movie "Blazing Saddles" .... we won't NEED their stinking oil to run our cars. :)

Y_Po said...

"they recently got an ultracapacitor order from McDonald Douglass for a military aircraft."
Say wha?

My guess they have been working on time machine too and it (unlike capacitor) is working.

richterm said...

I agree with you marc. It's a strange situation here with a private company's results holding the key to a public company's value.

Richard Weir owes the public nothing directly. He does owe his partners and customers at Zenn and LMC his best efforts in..

A) Producing a quality product

B) Helping wherever he can in meeting delivery schedules and in helping those customers meet expectations in the end products being promised.

I'm confident he is busting his azz on A). He seems to keep slipping on B - unless it's strictly Zenn's fault that the delivery of EESUs was promised for 2008.

The suspicious mind though could say that Eestor is operating from behind a cloak of immunity in making its promises. In theory I believe they could lie. In the end if they don't deliver and Zenn's stock price drops, I doubt there is any liability for Eestor. Personally I don't think that's what's going on here, but ZMC should really focus their attention on this and be more forthcoming on their reasons for confidence.

nekote said...

McDonald Douglass "merged" / was bought by Boeing in 1997.

Possibly an errant reference to another major Defense contractor - Lockheed Martin?

Bob said...

Richard Weir at IBM when?

If I remember, Weir ran disk drive manufacturing for IBM in the 1980s-90s.

They always had delays in delivery - my company loved it because we were competing with them.

That said, there was never a disk product that IBM failed to deliver, even if it was 6 months to a year late.

Generic said...

Anyway we can get a forum system set up?

Trying to keep up with the various conversations being held across the blog entries is becoming very tedious!

Alex said...

In 6 months to a year, Zenn will be worth $1. Looks like it may be time to get out while you still have a profit. Permittivity or no permittivity.

b said...

working on it generic

ApplewoodCourt said...

"There's nothing complex in this,"?

Well then, what's the hold up buster?

"I'm not going to make claims on when we're going to get product out there. That's between me and the customer. I don't want to tell the industry."

Isn't that interesting - this sounds a lot like someone who really has nothing but is simply bluffing. He wants everyone to think that he has something, but has ABSOLUTELY NOTHING TO SHOW FOR IT.

I'm sorry, but this whole thing stinks - it smells just like a company that I worked for during the .com / tech bust.

This really stinks in a fishy kind of way. The next sign will be someone in Zenn maybe the CFO, a VP or Clifford to make the announcement that they will be stepping down to spend more time with their family.

If Weir had any credibility or ANY product, he could wheel out SOMETHING - secretly packaged, of course - so as to not give any "secrets" away and attach it to something ... anything ... and do a quick demo - I work in an R and D environment, legit CEOs are stepping all over themselves to show demos and to take their wares to trade shows. We routinely engineer housings, hoods, etc. to hide the "goods" to show to potential customers, trade publications, etc. as do practically all other R&D firms. This indicates to me that Weir has nothing and will likely take down Zenn with it.

There is a company just down the street from me that was working on a super high capacity storage device that would revolutionize the digital storage industry - well, this device never made it off of the lab table after 2 years. In the interim, hard drive capacity have increased and prices have fallen so much that this "revolutionary" technology is now an expensive novelty - yes it is revolutionary, but ... 2 years of industry improvements in traditional technology have now caught up to the revolutionary technology - now, with the capacities being equal, the 2 would compete on price ... and the cheaper traditional technology wins.

If Eestor doesn't deliver in the near future - which I doubt that they will - Zenn will quickly fade into obscurity.

Moomipappa said...


To believe that Weir has nothing and knows it, yet continues to say he does, is to believe something quite implausible. If the tech doesn't work Weir has a few choices. First, he can say so and move on. Most of these kinds of things don't pan out so it's no disgrace. Second, he can get a salary for a couple of years until the money dries up but then face ridicule from his peers and disgrace in the community for misleading people - and make it very hard if not impossible to lead a project or get funding again. Furthermore, we have to believe that all the people working for Eestor know it's a sham but continue working there anyway.

As regards needing to deliver asap, that doesn't seem realistic. The EESU specified is quantum leaps ahead of anything on offer or even in the works. It's not just the storage capacity but also the ability to hold the charge and the speed of recharging that set it apart. Any of these on their own would be breakthroughs.

Alex said...


I and others agree that Zenn needs to comment on this latest article indicating yet another production delay. Is there anyway you can contact them to get feedback on this before we all start selling like madmen? Thx.

b said...

alex, you can always contact zenn directly on something like that. i've got an open request to speak with Ian Clifford...but I do know he has alot going on right now too.

ackkk said...


Or he can really believe he is 'just about there....if only we can get the powder a little purer.'

How many people are working for EEstor? Where are all the raw materials for 1,000,000 eesus?

ApplewoodCourt said...


Weir is playing poker and is bluffing. He has shown nothing and has proven nothing, the only thing that he has "done" is to make news in the form of a press release which states that a 3rd party lab has tested their equipment. Just like someone coming in to KFC to certify their chicken fryers ... "yes these chicken fryers can fry chickens at some number of degrees and yes, the employees know how to use the chicken fryer".

Colonel Weir: "Certifying our chicken fryers is a big step toward our fried chicken production goals"

When asked about when someone might actually be able to see some fried chicken Colonel Weir responded "I'm not going to make claims on when we're going to get product out there. That's between me and the customer. I don't want to tell the industry."

... but what about the fried chicken? "There's nothing complex in this," he says, pointing to his past engineering days at IBM. "It's nowhere near the complexity of disk-drive fabrication."

So Colonel Weir, you said that the chicken frying process wasn't very complex, when will we see some fried chicken? "This data says we hit the home run."

Colonel Weir, could I get some fries with my Eesu? "No comment"

ricinro said...

So Richard Weir is busy making a production line for the Emperors new clothes. I remember the tale enough to know that the fabric was so sheer it was invisible.
The EESU and its components are invisible as well, behind NDAs and specific business reasons.
Any concealed EESU prototype would not satisfy critics because it would still be invisible. Third party permittivity tests would help as well as seeing a unit in a zenn driving for half a day. There is the GM proving grounds a mile or so from my house and no one sees these vehicles in the flesh with the hood up until GM lets them. I don't really see too much difference here.
Some claim the technology is impossible and they may be correct but to venture that this is a hoax knowingly played on zenn, then VCs, then LM, then solar and wind partners...
Not too likely.
It was rumored that SMEs go in see the presentation, argue in technical terms, then come out grinning.
If it was the emperors new clothes the cynical SMEs would come out with a more cynical attitude.
Of course this is just rumor. But We know that at least three parties have been seen something and use a NDA as a poker face.
I can wait until eestor is ready. So far the delays are more indicative of real engineering development than a hoax.

Alex said...

I would like fries with mine :-)

ricinro said...

"How many people are working for EEstor? Where are all the raw materials for 1,000,000 eesus?"

Clearly from the images and further info from a Cedar park resident, eestor is in a building or part of a building that is less than 12000 sq feet. Any production line would be likely room size and processing small batches of powders. There is not any indication that they will be producing the volume off EESUs you cite in cedar park. Perhaps a few hundred for the initial order. Didn't Richard Weir mention that they want to make a few more production lines soon? Perhaps these will be located at other sites where materials can be delivered in bulk.

ApplewoodCourt said...

"It was rumored" that is just B.S.

Here I'll start a rumor just like the "grinning one" - "VCs left grinning because they couldn't believe that they had wasted their time flying all the way to Texas to listen to a used car sales pitch". This is no more valid than your rumor.

Here is our situation:
You have hundreds of scientists and engineers who have been working in the industry for decades when asked about the claims of Eestor - they say it can't be done.

Weir comes along and says "I did it" ... Scientists and engineers say "prove it" and Weir says "No, not gonna - can't make me".

Applying Occam's razor to this, we see that 1) we have some super secret mystery formulation which legit people claim can't be done but super secret mystery guy at company X without a website and located between the Yoga Wellness Center and car insurance company; won't actually demonstrate because "it's a secret" and "purity delays" or 2) It is just a scam like claims of "cold fusion".

Lensman said...

Moomipappa said...

To believe that Weir has nothing and knows it, yet continues to say he does, is to believe something quite implausible. [snip] Furthermore, we have to believe that all the people working for Eestor know it's a sham but continue working there anyway.

Actually, no. We only have to believe that the guy running the show is able to convince those working for him that he's got something, even when he doesn't.

I offer as an example: Thomas E. Bearden.


I hope just as much as anyone here that EEstor's claims turn out to be true. But things like this usually turn out to fail or to be scams, and I think it's foolish not to maintain a healthy skepticism unless and until an actual fully assembled EESU is tested by a qualified independent party.

- - - - - - - - - -

EEStor Fan said...

Like the mexican bandit says in the movie "Blazing Saddles" .... we won't NEED their stinking oil to run our cars. :)

Well, to be pedantic... Actually the line "Badges? We ain't got no badges. We don't need no badges. I don't have to show you any stinking badges!" is from "The Treasure of the Sierra Madre". The line was parodied in "Blazing Saddles", "The Freshman" and other movies.

richterm said...

applewoodcourt -

It is or it isn't. You have a right to by cynical and have your opinion as we all do, but that has no bearing on the ultimate truth.

I would LOVE some more info on Eestor - especially from Zenn since they have an obligation to shareholders. Eestor doesn't directly owe us anything. If Eestor really does have this working, I DO understand them being tight-lipped on it. As long as people as sure they're full of it, they won't seriously try to copy them. Head start. I also can see them being tight lipped if things are going wrong - but IMO Weir wouldn't be talking at all in that case.

Here's the situation that presents itself with a very high level of purity..

- If Eestor has the goods, the world will change, and those invested in Zenn will make a boatload of cash. Those who laughed will be even more bitter.

- If Eestor has nothing it will go on the cold fusion trash heap, and Zenn will be a penny stock.

Everybody knows the situation. Clear high risk/high return.

paulcummings55 said...

I have mentioned this before, but it seems most unfair to suspect those involved with EESTRO as perpetrating a scam. Look at those involved, and I do not believe that any of them has a 'huckster' track record- in fact, quite the opposite- so give these guys a break on their characater, regardles of whether the technology ever works or not. The second thing I would mention, is to go back re-view the Discovery Channel's Connectons series hosted by James Burke. One of the major premises of that show, was that result A would sometime come together with result B and produce the previously unknown and unanticipated result C- usually results that would significantly change the world. And usually these were things that could not have been anticipated- this is innovation- now, I am not saying the EESTOR technology is a shoe-in to work, history has shown us that innovation can come about most unexpectedly, even in ways that fly in the face of current understanding.

richterm said...


I hear what you're saying about not accusing those involved in running a scam. It doesn't seem fair.

However, we're at a point where there's little room to give Eestor the opportunity to potentially be "noble failures". They've claimed success after success. They've now come out to say they've tested prototype components. If you believe this, IT'S GOING TO WORK! How is it that they could not at this point know if they will get this working or not? They say they're putting in a production line. It must work. If it doesn't, what can we say about the principles involved?

On the whole I'm betting that they're not scammers - that they have this working. I'm going to see this through. But I'd be lying if I said I wasn't a bit antsy.

ApplewoodCourt said...

Another point:

"When we're producing batteries and everybody is happy, then we'll get a website."

If we take Weir at his word then we can conclude that he is not producing anything and that no one is happy.

Again, we have legit claims by professionals and scientists who have worked in the field for decades who review the facts as they know them and make statements that the claims by Eestor and Weir are misinformed at best and at worst, an outright fraud. These legit claims by people in the industry are pitted against those of Weir and company at Eestor - relative "newbies" to the energy storage industry - who somehow managed to whip up a world changing technology in the span of a few short years - but for some reason cannot or will not demonstrate any working prototype to the general public.

Again, you have two very distinctive camps - legit professional scientists and engineers with decades of experience who state facts and can cite formulas to back up their statements vs. dubious and secretive claimants who cloak themselves in secrecy, rumor and speculation, who only issue nebulous non-statements when pressed for details - and provide ABSOLUTELY NO VERIFIABLE PRODUCT, DATA or INFORMATION other than certifying that their deep fat fryer will fry at 400 degrees and that employees know how to use the fryer.

As someone pointed out, "it either is, or it is not" - I leave it up to you for you to decide - but the answer is very obvious to me.

My personal disclaimer - I have the day off and enjoy a spirited debate.

ricinro said...

Yes, I should refrain from repeating rumors and repeating stuff from unknown sources. I have seen wars started for less.

Indirectly the point I was making, albeit it is technically fantasy, is that the experts, scientists, and engineers that know better may still be correct about what they know AND learn something new. This is not unprecedented. I have seen less evidence to suggest this is oft-repeated game by a serial hoaxster.

ackkk said...


I don't know of a single person with good capacitor knowledge who says there is any chance that EEstor is on to something. Of course there will be skeptics. Among the skeptics who have posted here, I think there are very few who believe this thing is an outright scam.

I have been trolling for just one expert who might say "yes, there is a chance (albeit slim) that EEstor has an idea that might change what is known about this technology." I haven't found that expert.

I understand that EEstor might want to obscure what they're doing to throw off competition. But none of that can account for their BS press releases! Certification of the equipment is not something that needs to be publicly acknowledged! If your funders require certification, then show THEM the certificate! I don't require it! So why tell me?!

I think Weir et al truly believe/d they were/are onto something.

Nullpointer0 suggested this possibility (apologies if I mangle the sentiment): EEstor realizes there are problems/delays with the technology/schedule (a schedule that has been published by Zenn); when the product is delayed, znn is likely to nosedive; As a partner, EEstor feels a responsibility to Zenn; Zenn execs are heavily invested in/paid in znn; EEstor is able to release news of equipment certification (no lying), news that generates enough interest in znn allowing Zenn people to quietly get out of a portion of their investment before it becomes practically worthless. Later, EEstor revises its schedule to a 2010 (whenever) production date. All the while continuing to believe they are onto something (maybe they are.)

Nullpointer0's post was deleted! - Why?! - I have no f'ing idea, but don't like it. Maybe it was an accident.

I want to believe in this. I invested in znn. We are going to need this kind of technology in a world becoming increasingly disturbed by oil prices. My daughter is going to need something like this to work in order to have any kind of life similar to what I have enjoyed.

ApplewoodCourt said...

Really, this is my last comment for the day.

Company Profile: Eestor, Inc

Year Started:2001

State of Incorporation:N/A


Location Type: Single Location

Est. Employees:9

Est. Employees at Location:9

Contact Name:Richard D Weir

Contact Title:President


So, we've got 9 employees ...

1) Weir
2) The other co-founder
3) Weir's wife
4) Secretary / receptionist if #3 isn't doing these duties ...

So, basically we are looking at half the company.

I'm not seeing the ramp up - no employees, no other corporate sites - all easily verifiable by corporate records.

I know, I know ... the hundreds of others are contractors and they are hidden in a super secret bunker in the Texas hill country.

Have a good evening.

richterm said...

applewood -

The answer may be very clear to you. It's not so clear to me though I'm on the positive side. In the end, neither of our opinions nor anyone's will matter in forming the result.

One thing I've noticed about opinions of experts in the field. Many claim to be experts on message boards and seem to have claims based on decent knowledge. But I haven't read one article where an expert says "No way". They're not going on record. Shouldn't somebody if this is doomed to fail for elementary reasons?

Marcus said...

richterm, what would the legal ramifications of such a statement be whether they were legit or not?

ricinro said...

Experts keeping an open mind?

Lends them credibility IMO.

Joao said...


I hope that I am not doing anything illegal or inappropriate by re posting here a comment originally posted by "cobraphx" on a discussion on EEstor on "Technology Review". The link to the original comment is http://www.technologyreview.com/read_article.aspx?ch=specialsections&sc=batteries&id=20090&a=#comment-201172

Basically it tells how the Blue LED was born and how similar it looks to the situation with EEstor.

"Everytime I hear this stuff about the math in the patent and experts in the field it reminds me of the Blue LED. Does anyone remember the birth of the Blue LED? It was perfected by Shuji Nakamura while working at Nichia (A small, pretty much unknown Japanese chemical company). Nakamura took a path most scientists in the field had discounted as unworkable. But this lone researcher and his hunch payed off.

---"Meanwhile, back in November 1993, Nichia announced its blue LED, promising at the same time that a blue laser was under development. Nichia's devices are made from an entirely different compound material, gallium nitride. The announcement caught the rest of the industry with its pants down. Gallium nitride had long been written off as fatally flawed. Making a diode requires both positive and negative types of material, and no one had been able to make positive-type gallium nitride."---

Interview at: http://www.sciencewatch.com/jan-feb2000/sw_jan-feb2000_page4.htm
SW: What was it about zinc selenide that made it seem so superior?

Nakamura: The crystal quality of zinc selenide is very good. The dislocation density, which is a measure of the number of defects in the crystal, was less than 10^3 per cubic centimeter. Gallium nitride was more than 10^10 per cubic centimeter. And when people wanted to make reliable LEDs and laser diodes, they knew that the dislocation density has to be lower than 10^3 or even 10^2. This is just physics.

SW: That sounds almost insurmountable. How did you get around that defect problem?

Nakamura: Well,first I needed a MOCVD reactor. MOCVD stands for "metal organic chemical vapor deposition." Since I had money now, I bought a commercial reactor and used it to grow gallium nitride crystals, but I couldn’t get them to grow on the substrate. So I spent two years modifying my commercial reactor and succeeded in making what I called the two-flow MOCVD reactor. Usually a MOCVD has only one gas flow. That’s a reactive gas that blows parallel to the substrate. I added another subflow, with an inactive gas blowing perpendicular to the substrate. That suppressed the large thermal convection you get when you’re trying to grow a crystal at 1,000 degrees. Using this two-flow MOCVD I succeeded in 1991 in making the highest quality of gallium nitride crystals in the world. The dislocatoin density was still 10^10. But there’s another measure of crystal quality, which is hole mobility, and I achieved a hole mobility of 200. That was a world record. The highest hole mobility ever achieved with gallium nitride was 100.

SW: So the two-flow MOCVD reactor was the key breakthrough?

Nakamura: Yes—suddenly it was easy to make any type of gallium nitride. In 1991, I made n-type gallium nitride. The following year I succeeded making p-type using a thermal annealing technique. Now all gallium nitride researchers use my technique for p-type gallium nitride. Another big breakthrough was making the first single crystal of indium gallium nitride, which we needed for an emitting layer. Finally at the end of 1993, I succeeded in making the first commercial-based blue LEDs."------

Seems to me industry expert's aren't always right. Especially when they say, "this material can't do x because of y". Same was said of gallium nitride, can't make a diode because of defects. Sometimes another property can be leveraged, or the side effect of a undesirable property can be mitigated like in Blue LED. Properties of materials change when talking about the nano-scale (EEStor is using barium titanate nanoparticles). Look at carbon nanotubes, a block of carbon is weak, but a bundle of carbon nanotubes is very strong.

Keep in mind that there isn't a single advantage to EEStor to show anything to anyone outside an NDA. Can anyone name a single thing? Will you boycott their tech because they didn't prove it worked before it was commercially available? The market is so huge, they can't possibly meet demand if when they start production. They don't need to buy goodwill, or build customer confidence. By giving out information, they do risk other companies catching up to them. If you leak the key information about why it works in spite the math, how long would it be before one of the capacitor experts duplicated it? Of course this is all moot if their tech doesn't work. EEStor isn't Nichia, but it's possible that they are the next Nichia."

richterm said...

marcus -

IMO - I don't see any ramifications. As long as the expert framed it as his/her technical opinion based on patents etc. I think more of an issue is not wanting to look stupid later.

seslaprime said...

I think the skeptics do not realize that Wier had the science already figured out before EEstor ever told anyone about their idea. They built proto-types and tested them vigorously before going to KPCB, Zenn and LM. these investors gave their money because they knew for sure Wier's invention worked. the question never has been weather Wier could make this device work as planned, rather can Wier mass produce the device and still meet the permitivity requirements needed so the mass produced device is as realistic as the proto-type device. from Wier's perspective, this has been his Only challenge. they are excited today because they have met and exceeded the production facility requirements. as far as skeptics not understanding the science, it is obvious that Wier has cleverly hidden the total picture through a series of patents, most of which are still in process and cannot be examined. No one will be able to figure this science out soley on the few patents that are in public record. Wier does Not want to be competing against his own invention before he even gets out of the gate. Richard Wier is a Brilliant innovator, CEO and leader. He knows the industry and how to surroud himself with the right people. The EESU is a Huge step towards energy independence not only for the US, but for the entire world.

TomBfromLouisiana said...

Well said Seslaprime.

I think you hit the nail on the head.

Folks, sometimes you have to have a little trust and faith in people. If Weir and the rest of the EEstor people are "scamming" then you must ask yourself how and why they have been able to do it since 2001?

Weir seems like a brilliant man who could be devoting his time and effort to something much more productive and lucrative rather than risking his reputation taking the VC people, Zenn and LMT for a ride.

Weir has a proven track record of success and a good team of investors behind him and a "billionaire" on his Board of Directors..

If he sold all three of these companies he must have something or he is the next P.T. Barnum!

I bought some Zenn stock last week, bought some today and I look forward to buying more in the coming weeks and months and hopefully laugh all the way to the bank.

Nothing ventured, nothing gained.

Tom Villars said...

Bob said, "That said, there was never a disk product that IBM failed to deliver, even if it was 6 months to a year late."

The company you worked for, did they ship in comparable quantities to IBM, or was your volume much lower?

mrjerry said...

I found another piece of the puzzle,
Fenwick & West

Representative Transactions
Represented Kleiner, Perkins Caufield & Byers on numerous cleantech investments, including Bloom Energy, EEStor, GreatPoint Energy and Miasole.

Fenwick & West is a national law firm that provides comprehensive legal services to technology and life sciences clients of national and international prominence. We have over 275 attorneys, with offices in Silicon Valley, San Francisco, Seattle and Boise.

richterm said...

tomb - that's my thinking too, though I have my moments of uncertainty.

On the whole I feel it's a 75% shot at making anywhere between a 10x and 40x gain, maybe more.

weird_science said...

Does anyone have Eestor's address in Cedar Park?

Book-em-Dano said...

In my estimation, 35% or more of EEStor's potential revenue could depend on applications that rely on an EESU's power density (dependant on SI: series impedence) spec - from industrial (very low SI) to military (extremely low SI).

I'm beginning to suspect that LMC has been involved with EEStor in some way, shape or form, for significantly longer than admitted publicly.

I can't find ANY reference to SE or even a spec I could use to derive it, anywhere - either in "component" form or built-up commercial-grade EESU "module", except for a grossly unreliable off-hand remark about minimum discharge time in an old article.

For a manufacturer to report a product which has, as far as its specific economic sector is concerned, energy & power density as its main criteria, without actually reporting power density, is unheard of.

In the WIPO patent, "interface electronics" which is not even part of the patent claims, is cited as a limiting factor, and used in place of stating this critical specification. The filing date on the patent is 4 years ago.

Does any other electrical / electronics tech-related individual have an opinion about this?


TechB said...

I find it odd that so many people have to come to an absolute decision on this topic. I am an electronics technican and am familiar with the basics physics of capacitors and I have read everything I can find on EESTOR and have come to the conclusion there is just not enough information to know for sure. We are just going to have to be patient and take a wait and see approach. I fervently hope the claims are true. It would be totally awesome. That said,I bought enough ZENN stock that if EESTOR comes through, it will be a nice addition to my retirement, if not, it won't hurt me to bad.Just my two cents worth.

Marcus said...

Actually I think a lot of us take the same position techb.

Tom Villars said...


Just curious how long you've been reading up on EEStor?

One thing that struck me about Tyler's article was the only people with names, Weir, Clifford, and Dahn where positive while the skeptics where anonymous. I'm curious if that pattern has been consistent over the last several years, is it something new or the size of the data set is to small to tell.

Y_Po said...

Skeptics have nothing to gain by going public. But if Mr. Weir want to bet I would like it very much

richterm said...

Why wouldn't you have something to gain y_po?

Call up Tyler Hamilton and tell him you'd like to contribute to an in-depth analysis of why Eestor is the impossible dream. With your name on it. Then, when you're proven correct you'll be known in the industry as an ultracap expert and can offer very high-priced consulting services to any VC firm that thinks of investing in an ultracap startup in the future. At the very least you can link to the article on your resume.

Y_Po said...

I doubt i would be regarded as an expert, because the rest of the experts would say "Big deal, we knew it would not work too"

If only they were saying it would work and I proved it would not. In this case yes, it would be big deal.

richterm said...

But no one else is going on record.

Come on, be a star y_po. We can all say we knew you back when you were an anonymous blog poster. No one else is bold enough. Show the world you're bold.

Glen said...

Tyler Hamilton has more on his interview with Dick Weir on his Clean Break site. Apparently LM is much more involved than previously thought.

Marcus said...

glen you beat me to it. I have to say that the deeper LM relationship cited builds confidence that thorough technical due diligence by LM has been done.

Christine said...

Hello everyone.
I have read everything that has been posted since last Wednesday and feel I am up to speed. We had a death in the family and that is the reason for my sudden departure. Thank you for your concern johng and others.
I have discussed EEStor with my dissertation adviser and he is an SME. He published 2 papers on BaTiO3 last year and he has published papers and journal articles on dielectric materials, among other things, since I have known him and that has been 19 years.
He is a tenured Full Professor of Ceramic Engineering at a major US engineering school. He is fully aware of EEStor and though he wishes them well he states that they definitely have there work cut out for them. When I described the WIPO patent to him he simply stated that Nano-Dielectrics have been a field of great interest and excitement for at least the last 10 years and that he is not aware of any breakthroughs that have been published.
Nano-Dielectrics is not a term that I have read on any blog over the last two years. The idea of nano technologies is that when you approach the very small you enter a realm where classical mechanics no longer dominate and Quantum mechanics start to dominate. Properties of materials can be very different realm of the very small. Nano engineering is the art of designing and building materials in which you can accentuate the quantum behaviors on the macroscopic level.
So if this is EEStor's gig, then let me tell you this is not your father's capacitor.
Tomorrow night I will post a list of papers going back as far as 1948 talking about properties of single domain BaTiO3 along with a summary of each. I can pull the papers for free because where I work makes everything scientific available to me. I believe that anyone may be able to read the abstracts for these papers on line for free.
y_po Whenever I interview someone who tells me they are a Physicist I always ask "What is the central problem in Physics today?" I ask this even though it has nothing to do with the job they are applying for. I ask it because I believe that it tells me something fundamental about them. You need to answer this question correctly or I will not even acknowledge you again.
I am going to bed now.

Y_Po said...
This comment has been removed by the author.
Y_Po said...

glen you beat me to it. I have to say that the deeper LM relationship cited builds confidence that thorough technical due diligence by LM has been done.

I did not get that impression, I see Tyler got this impression but looking at Weir words all I can see is use of LM as an excuse for yet another delay.
This recent increase of PR (useless anyway) looks like if EEstor is trying to satisfy bloggers.

Y_Po said...

What is the central problem in Physics today?"

That's probably most nonsensical question I have ever heard.

And I am sorry, but you had no clue what "domain" is.

Marcus said...

I can feel the heat building....I think there's gonna be some sparks a flying!

Satya51 said...

"Tomorrow night I will post a list of papers going back as far as 1948 talking about properties of single domain BaTiO3 along with a summary of each. "

Thanks for returning Christine, the summaries would be most kind, everyone here will be in your debt.

Anonymous said...

Like Glen already said, Tyler Hamilton's Clean Break has more of his interview with Weir than Tech Review does. I'll provide a link: Another chapter in EEStory

mjtimber said...


Why are your posts so negative? When someone writes a civil, constructive post, you feel the need to respond with a complete lack of dignity. Here's an idea: try constructive criticism instead of trying to tear people down.

It's possible to be both informative and pleasant. You really don't have to choose. Now go ahead and rip me a new one, I can take it.

By the way, why not take B up on his offer to post your ideas in a coherent, thoughful manner? I think most of us would rather see a fully realized explanation of your ideas rather than the piece meal process of going through all your caustic posts. Thanks.

Satya51 said...

Thanks for pointing out the additional information on Eestor from Tyler Hamilton on Clean Break. It was insightful. And thanks for the link Mihkel.

Also it is important to recognize that mass production of components is just part of going commercial. Additional lines will need to be in place, electronics, etc.

Since the production line chemicals will meet the military specs (twice the energy storage, assumed from operation at 5000 V vs commercial operation at 3500 V) I wonder why the commercial ESU's won't carry the same rating?

Book-em-Dano said...

- Christine

I'm sorry to hear about the death in your family, although I must admit I'm also very pleased to see you back in the discussion.

Your previous posts left the impression of a tenured proffessor performing a cross examination during a dissertation. I see it was the other way around.

Good luck.


To reconcile the very small with the very large.


Y_Po said...

Why are your posts so negative?
Don't know, may because her post was negative?

Marcus said...

To be fair to Y_Po, go and have a look at the initial exchange. I think I correctly summarized the interaction when I described them both trying to guess what the other was talking about. I think the blame could be spread equally. In fact notice it was me that got the blunt end of the stick in the end and for what? I was trying to help!

Marcus said...

Although a death in the family is certainly a good reason to be upset.

Marcus said...

BTY christine, let me take a stab. How about reconciling quantum mechanics with relativity?

Moomipappa said...

"That's probably most nonsensical question I have ever heard."

I can easily beat that:

"What is half of salmon?"
"Who was the first person to sausage?"
"What is the difference between jumping?"

johng said...

I am traveling,so I dont have the specifics, but on the plane, I was thinking.

The WIPO patent that everyone points to as demonstrating the voltage stability and the overall qualification of the device, had no problems.

Why aren't they just duplicating that? Why has it taken five years to get to making the BT...obviously, the old BT was good enough.

Satya51 said...

"Why has it taken five years to get to making the BT...obviously, the old BT was good enough."

Economic mass production of the BT looks to be the key to that delay. It also looks like a further delay was to get to a 5000V product so that they could give LM the military spec product of twice the storage. imho

Satya51 said...

Christine said, "Nano-Dielectrics is not a term that I have read on any blog over the last two years. The idea of nano technologies is that when you approach the very small you enter a realm where classical mechanics no longer dominate and Quantum mechanics start to dominate. Properties of materials can be very different realm of the very small. Nano engineering is the art of designing and building materials in which you can accentuate the quantum behaviors on the macroscopic level.
So if this is EEStor's gig, then let me tell you this is not your father's capacitor."

Yet, all your computations show no reflection of this understanding of quantum behavior at the nano level. But that does not stop you confidently implying that Eestor is clueless because your computations don't allow their claims.

There seems to me to be some overconfidence there. Although you may not think so, I think there is a lot we can learn from Christine on this forum, and it may help us in understanding what a competitor would have to do to leap frog Eestor. R. Weir seems to think that Eestor has a good headstart. From Tyler Hamilton, "He hinted that he was expecting competitors to challenge EEStor, and that his advantage will be the ability to move quickly and stay several steps ahead. "If we get challenged, we'll move to scale up," he said. "We have a lot of knowledge built up.""

I suspect that a lot of nano technology these days goes unpublished, and although there are at least 10 outstanding physics conundrums facing modern physicists (book_em_dano mentioned one), I would say that the problem with not publishing is certainly a big problem for todays physicists.
So, here's to learning,

b said...

hey christine, could you shoot me an email? i have an idea for your articles. eestorblog@gmail.com

ps sorry to hear of your loss.

zawy said...

"What is half of salmon?"

One bear bite.

"Who was the first person to sausage?"


"What is the difference between jumping?"


"What is the central problem in physics today?"

Physicists aren't smart enough to carry it any further any faster.

zawy said...

...PS...and that they haven't mass-produced a good energy-storage device yet.

aaron said...
This comment has been removed by the author.
aaron said...

Christine, in Y_Po's defense, and I do not know this man from "Adam", it seems like a pretty narrow band of thought that could potentially remove credibility from the wise.
A single question?
Is that not exactly the reason Quantum Mechanics and General Relativity seems so alien to one another? If that is indeed your answer. Our brains function as a network, but our logic is single threaded it seems when dealing with things we do not understand. Is it possible that something is and isn't simultaneaously? That is, for Y_Po to be right about his analysis and wrong about your answer?

I'll add one question to the mix.

Is this a good question?

Satya51 said...

Thanks for the link to the patent for the quantum super capacitor. Coincidentally, the energy density claimed is just slightly more than Eestor's ESU. The mechanism for energy storage made my eyes cross trying to understand it.

Really good find and ties into what Christine was implying.

johng said...


You may know this, but a Proff Buonjouno Nardelli at NC state has been doing the Quantum Mechanics development of BT theory. He is a nice fellow who will surely discuss it with you.

zawy said...

What does this nice professor conclude about EEStor? Christine's professor only said it will be difficult. It would be nice if we had someone else with credentials and to show why or why not.

zawy said...

Satya or Maruc, what patent on quantum capacitor?

Y_Po said...
This comment has been removed by the author.
Marcus said...

The one I referenced yesterday that you have already commented on.


Y_Po said...

I really don't know how to react here. So I will just point inconsistencies.
1. There is no "classical" physics in material science, it has always been QM. Without QM material science reduces to Hooke's law and nothing else.
2. "nano" is called "nano" for a reason. 1 micron is not nano technology.
3. I am extremely suspicious of "experts" (Weir and Christine included) which never heard or don't know about dielectric saturation.

Satya51 said...

Also, just go to google patent search and put in quantum supercapacitor. It was really a super find by Marcus as the patent goes into the theory. It makes no sense to me but it might help someone else.

zawy said...

The patent says the technology EEStor is using currently cannot exceed 2 MJ/kg and that there is no theory that allows it to exceed 20 MJ/kg, and that their quantum method can achieve 1.7 MJ/kg. EEStor is claiming 1.7 MJ/kg. Yes, good find.

Marcus said...

zawy, yesterday you told me

"That's only 300 J/cc, 35 times less than eestor 11,000 J/cc."

Did I misquote the paper when I reported their energy density to you?


zawy said...

I made a math error yesterday, dividing by 6 instead of multiplying. Big oops.

Satya51 said...

It will be interesting to hear what Christine has to say about the theory mentioned in the patent. I wonder if there is a paper on this quantum supercapacitor?

zawy said...

relevant quote from it:

"A most effective method is nanostructuring of dielectrics such as BaTiO3 by creation of nanosize clusters with a shell [EEStor], or creation of thin nanosize films with metal doping. With the help of such an approach, it is possible to increase permittivity up to 10,000 to 100,00 and to achieve specific capacity (huh?) on the order of 100-1000 F/cm^3 (huh?). In result, it is possible to receive specific energy reserved in the capacitor of on the order of 2-20 MJ/kg."

"[with EEStor-type] a high degree metals doping is used. It results in the transformation of dielectric to the semiconductor. In result, there is large leakage current that results in rapid loss of the stored energy. Hence, the application of such capacitors for long-term storage of energy is not effective"

That might support the idea that electron movement is the source of the large dipole I've been looking for. The alumina and PET would prevent leakage.

It doesn't resolve the series capacitance problem.

zawy said...

OK, that's it for energy density. I can see it might be possible. Electron movement can create the surface charge y_po seeks and it explains my dipoles. I would think that surface charge doesn't all have to be "at the surface" but can be in several layers below to add up to more than 1 e per A^2. The energy is stored in the charge separation and the charges apparently snap back from different sides of the CMBT thanks to attraction to each other.

So unless y_po claim explain how the above is not possible, I'll fall for the 3 patents and the 3 big investors' story.

OK, now for capacitance. Can any of you sleuths find a corundum of aluminum oxide that has a k above 100 or is a semiconductor? Then that would leave only PET causing a low k which can be squeezed or something.

Y_Po said...
This comment has been removed by the author.
Y_Po said...

You take another patent as a solid theory/experimental fact :)

And no, you can't increase limit on polarization/surface charge. What you suggest is irreversible process

zawy said...

Electrons can't be dislocated in a semiconductor and return once the field is removed? Can you give me some buzz words in physics that speak about this limitation so that i can go teach myself?

If electrons are moving around like this then the average of the dipole moments could satisfy the equation I got from feynman. The E field could have a slow instead of sudden drop when going into the dielectric. The k would be on the order of 100 near the surface because the electrons can't exceed your limit of 1/10th e per A^2. Energy storage would be less there. It would take at least 40 layers of the lattice being like this before reaching EEStor's 11,000 J/cc. I would think the same situation applies to the metal plates (a few layers of surface charge to hold all the electrons). As Feynman emphasized, the common form of maxwell's equations are no good for dielectrics because they don't allow for a varying k.

Y_Po said...

Electrons can't be dislocated in a semiconductor and return once the field is removed?

They can. But you have to choose it is either conductor or non conductor.

If you choose conductor then electrons can move as far as you like but you would not be able to store any energy this way

zawy said...

Maybe the energy is stored in the "pulling out" of the electron to turn it from insulator to conductor. In a conductor the charges are moving freely and don't have anyplace to "snap-back" into.

Do you think a varying k with depth is a valid way to get around the surface charge limitation?

Marcus said...

For the technically minded, I think this paper may be highly relevant to the mixing rule conundrum associated with the world patent. If you cannot access it I will post sections. Here is a tid bit.

While the ferroelectric ceramic-polymer composites generally show an increasing effective dielectric constant with increasing ceramic volume fraction, which is in good agreement with the mixing rule, metal-polymer composites show an abrupt rise in the dielectric constant near the percolation threshold of metal. Therefore, the dielectric constant of the metal-polymer composite can become much larger than that of the polymer matrix [3]–[5].

Dielectric properties of Ni-coated BaTiO3-PMMA composite
Author(s): Park JM (Park, Jung Min), Lee HY (Lee, Hee Young), Kim JJ (Kim, Jeong-Joo), Park ET (Park, Eun Tae), Chung YK (Chung, Yul-Kyo)

Marcus said...

To continue the intro,

However, the dielectric loss also increases very rapidly near the threshold, which limits the use of 2-phase composites in actual devices. In order to further enhance the dielectric properties of polymer-based composites, 3-phase composites, consisting of ceramic, metal, and polymer phases, have attracted significant attention due to higher dielectric constant feasibility with low processing temperature. We have reported the role of high K BaTiO3 filler and Ni particle size in Ni-BaTiO3-PMMA (polymethyl methacrylate) composites, where both Ni and BaTiO3 particles are dispersed in the polymer matrix [6], [7]. The alternative composite can also be made from BaTiO3 particles coated with thin Ni layer, which is the topic of this paper.

Y_Po said...

None of it address main problem - dielectric saturation. I said before - there is no clear limit on permittivity, it can be 20,000, 200,0000 or a million.

In any case If you mix metal with dielectric you should expect increase of k (compared to just dielectric)

jam said...

That's more like it.

The dielectric value of the polymer increases from ~ 4 to ~10 :) :) :)

Marcus said...

Well, its the most similar 3-phase composite to EESTOR's that I've found published data for. Sorry if it doesn't shed any new light.

OntarioInvestor said...

I can verify that ZNN will be moving to the NASDAQ. In fact, it is more likely that they will first move to the NASDAQ prior to them moving to the TSX main board from the venture.

larry said...

new here and not as up on the science as others here. I understand that a high k of 18000 plus is good and needed, but that if the electrodes can't hold enough charge, ie become saturated, you don't get the energy storage quoted. Seems to me, if k were a problem, just make the center material thicker, of course at loss of energy density. But if the electrodes can't hold enough electrons or holes, that's another problem. So, for simple me, can anyone tell me if saturation is a problem; can the materials hold the required charge?

Satya51 said...

Any idea when that is likely to happen?

Tom Villars said...


Moving to the NASDAQ like that would be a bit unusual. Do you have link for this or is this a friend of friend type of info?

mrjerry said...


Zenn said in their annual meeting march 31st that their was plan to go to the nyx or NASDAQ. So this is possible could be in the works, notice how quiet zenn has been lately.. if they had a product, and wanted to show you have the goods, you probably want to be on the us exchange. It important to know that there is a lot of planning that has been in the works, everything is strategic at this point.

Rod said...


Hey I am rooting for you, wait don’t say it, you don’t need anyone rooting for you. Anyway, its getting a little boring since you went to the one-liners. A week ago or so I could count on reading some real science from you and the debate was intriguing, wait I know…not intriguing for you because you see this so simply. But for the rest of us that want to see two sides, can you find it within yourself to get back into the game with your science and confidence, take these guys on again with the science…do it all over again like you did a couple of weeks ago, that’s all been forgotten and you need to do it again. You’re above the one-liner come backs, get back in style, give me the math on electron energy densities or something please. I miss that.


zawy said...

As the V/um raises above 1 V/um (the limit for storing 10 J/cc at k=22,000), electrons have to be broken free and easily migrate to the surface. They cancel the V/um on the interior. New electrons will be broken free for each small increase in V/um. If my ciphering is correct, only 5% of CMBT has supply and hold an extra e- to be able to do this so that at 350 V/um applied, the only location of < 1 V/um (non breakdown) is 1200 layers deep, near the center of a 1 um particle. I want the maximum depth because the theory is that the vast majority of energy stored is from transition to breakdown.

zawy said...

If 40% of the CMBT cells donated one electron, 10 eV would have to be the energy required to break each one free in order to absorb 10,000 J/cc. I don't know semiconductor physics so i don't know if that's possible or 99% reversible.