TheEEStory.com

manthan33 wrote:

so they dont have a prototype?

eestorblog wrote:

It's very interesting to me that so many act as if EEStor hasn't demonstrated anything. Really? Exactly how would you know that? Please enlighten me. Are you a member of the board of directors?

What you need to do to repair your statement is to say that Weir and team have not allowed a public demonstration. There's an enormous difference.

nekote wrote:

Yes, cables / wire probably would get away with it, for a few seconds at a whack.

My point was more about 20A @ 24V (480 Watts) vs 26,000 Watts (for 90 second recharge).

Gotta' be different interfaces.
"Specialized charger" gotta' have a (second) EESU that is slowly charged over time, but can punch out one helluva' whallop (26 kW), to transfer ~650 Wh in 90 seconds (.025 hours)

I think I agree with your conclusion, just not that the wires are the weak point. I would say the semiconductors and then the magnetics.

But we are trying to read the tea leaves left by a cup of coffee.

Robert

Steve321 wrote:

manthan33 wrote:

so they dont have a prototype?

According to B there are EESU's but Weir and team have not allowed a public demonstration.

eestorblog wrote:

It's very interesting to me that so many act as if EEStor hasn't demonstrated anything. Really? Exactly how would you know that? Please enlighten me. Are you a member of the board of directors?

What you need to do to repair your statement is to say that Weir and team have not allowed a public demonstration. There's an enormous difference.

Only proves that there is no public proof one way or another, only circumstantial evidence (mostly heresay)

Robert wrote:

nekote wrote:

Yes, cables / wire probably would get away with it, for a few seconds at a whack.

My point was more about 20A @ 24V (480 Watts) vs 26,000 Watts (for 90 second recharge).

Gotta' be different interfaces.
"Specialized charger" gotta' have a (second) EESU that is slowly charged over time, but can punch out one helluva' whallop (26 kW), to transfer ~650 Wh in 90 seconds (.025 hours)

I think I agree with your conclusion, just not that the wires are the weak point. I would say the semiconductors and then the magnetics.

But we are trying to read the tea leaves left by a cup of coffee.

Robert

Unless overdesigned quite a bit, I'd say the electronics would be a weak link in this device.

I concede the point to Robert and dfwrunner, about the electronics being the weak point.

FWIW, 26,000W, at a fixed linear rate, at 3500V, would be 7.4 Amps.

tvillars wrote:

The price per kWh looks to be about $100. This bodes well for ZMC's 15 and 52 kWh EESUs as presumably the price per kWh will drop as total capacity goes up.

Beyond that, potentially having settled on a 640 Wh unit as one basic configuartion, would be super excellent, most especially if ganging them together for 15 kWh and 52 kWh units is part of the deal.

Sure hope they were that clever / forward thinking!

640 Wh is about the same as my electric bike. Big difference is I can only safely discharge my bike about 60% and the batteries weigh 35 lbs.

Looking through the trademark office, I see an application for the word EEStor also. Looks like the same dates and same example used.

http://tmportal.uspto.gov/external/portal/tow?S...

Thanks for the pleasant surprise, B. This makes for a nice new year present, next to the ultimate.

Robert wrote:

This 'specification', however, appears to be fabricated out of whole cloth.

Could you please expound on this? What is it that indicates the specs are fabricated? And if it can be explained in layman's terms, I'd be most grateful.

I don't want to burst to many bubbles here, but what B posted is a "wish spec sheet" by EESTOR. It proves nadda, nothing. It doesn't speak highly of EESTOR if it took them seven years (FIRST USE ANYWHERE DATE At least as early as 02/02/2001 per filing) to develop the spec sheet and still no product. Now the question is how many years will it take EESTOR to manufacture an EESU meeting the specs, or if they ever will achieve the specs? It's typical B trying to cheer up the believers and pump up EESTOR.

BTW-anyone can submit "Specimans" for a fee to the United States Patent and Trademark Office. Again it proves nothing.

Happy New Year

A correction note.
BradF pointed out that charging a capacitor is a non-linear deal.
Thus a requirement for double the current, compared to linear.
Please double any linear amperages calculated, for a better true Amp figure.

.

Also, Steve321 could easily be correct.
Just a "wish list" spec. - a "for instance".

One reason I can offer is the minimum operating temperature is listed as -40°C .
ZENN switched from -40°C to -20°C (-4°F) some time ago.
Causing concern about colder climates.

Would be nice to know what the lowest temperature really is.
And what happens, below that!
(temporarily fails to operate - requiring heater?)
(permanent damage - akin to non-antifreeze coolant cracking an engine block?)

.

Another reason it could be a "wish list" is the Maximum Storage Temperature listed is 150°C .
I would think getting above the Curie temperature of ~120°C would be a bad thing. A very bad thing for a fully charged EESU.

.

Lastly, the odd mis-match on the volume: 9.44 x 10^5 mm^3 (101.6 mm cubed)

In summary, some of these parameters aren't vetted?

Last edited Thu, 01 Jan 2009, 5:40pm by nekote

nekote,
The company I work for does use the term "wish spec list"...I can't take credit for that term:). The R&D department submits to the design engineers a "wish spec list", and I could say the majority of the times the final "production spec list" differs from the original "wish". That is why I stated the "Speciman" that was submitted to the United States Patent and Trademark Office on Dec. 13, 2007 by EESTOR means nothing.
If EESTOR ever commercially produces an EESU I can guarantee the final product spec list will not be the same as the submitted.

Daniel R Plante wrote:

And no, the "unit" will not require "magnetics",

It will if it's going to produce 24V from from 3500V.

The reference to magnetics being a weak point was referring to there only being a single bus to charge from, therefore rapid charging would require large currents.

hmm, I can see a partial way around that if you don't allow current to flow into the pack under normal use. I don't think it would allow a 90sec charge but I'll have to work it out.

Robert

Lensman wrote:

Robert wrote:

This 'specification', however, appears to be fabricated out of whole cloth.

Could you please expound on this? What is it that indicates the specs are fabricated? And if it can be explained in layman's terms, I'd be most grateful.

Let's see
it's not internally inconsistent (wouldn't be the first spec sheet with an error though)
49C is a very odd upper limit, especially w/o derating information
the certification note is useless
and finally it has pricing, spec sheets never have pricing for obvious reasons

Really though, it boils done to something I can't quite put my finger on, every spec I've seen worded and displayed in this fashion has been fictional. Either for a product not yet built (and so a fanciful wished for specification list that would be later revealed as too optimistic) or as an exemplar for a custom product (and further inquiry would reveal that not all specifications could be met at the same time).

Robert

nekote wrote:

A correction note.
BradF pointed out that charging a capacitor is a non-linear deal.
Thus a requirement for double the current, compared to linear.

You can easily charge a cap with a fixed current source (or is fixed power source). A fixed power source will be faster if the peak power restrictions are the same. A fixed current source is simpler. In either case the energy required is simply the AH rating * the bus voltage (adjusted for efficiency).

Robert wrote:

hmm, I can see a partial way around that if you don't allow current to flow into the pack under normal use. I don't think it would allow a 90sec charge but I'll have to work it out.

Yep, there is a charge route, limited probably by the semiconductors but maybe the magnetics. You can send 20A back through a standard non-isolated buck converter with the voltage rising as the cap charges. The voltage will rise linearly. The charge will be quite rapid at 20A, I work out about 70s. Add in some margin for losses and...

It would leave the device open to a single point failure putting high voltage on the bus when in use though.

Robert

Last edited Thu, 01 Jan 2009, 4:02pm by Robert

Robert, suggesting using 24VDC and 20A as input power, rather than output?

yhr semiconductors? your semiconductors?

"voltage will rise linearly" - referring to the 24VDC (or what ever) input voltage? Or the voltage at the capacitor terminals?

Rising linearly to what final voltage?
3500V (or 5000V)?

Not something possible from ordinary household 120VAC (or 240VAC, for that matter) in 90 seconds, is it?

the volume 101.6^2mm3 vs 944000mm3 is about 11%

101.6mm equal 4 inches. This is typical in the US. EEStor uses the metric system but describes the size in inches for American ears. The numbers are close enough.

nekote wrote:

Robert, suggesting using 24VDC and 20A as input power, rather than output?

The same terminals.

nekote wrote:

yhr semiconductors? your semiconductors?

They become passives. The switching device will look like a diode to the charger. I can draw the concept if you would like.

nekote wrote:

"voltage will rise linearly" - referring to the 24VDC (or what ever) input voltage? Or the voltage at the capacitor terminals?

Rising linearly to what final voltage?
3500V (or 5000V)?

The voltage on both the capacitor terminals and the output terminals. Final voltage on the terminals (before disconnecting from the charger would be close to that on the capacitor. Obviously any output capacitor on the DC-DC would need to be discharged before allowing the pack to be used.

nekote wrote:

Not something possible from ordinary household 120VAC (or 240VAC, for that matter) in 90 seconds, is it?

20A @ 3500V = 70kW

580A or so at 120V, you'd need a pretty good service. A slower constant current/constant power charger using the same basic scheme would be possible though. Just slower.

My big concern would be safety but I can see ways of tackling that.

Robert

nekote wrote:

yhr semiconductors? your semiconductors?

Oops, should be the. I will fix.

Robert

Steve321 wrote:

nekote,
The company I work for does use the term "wish spec list"...I can't take credit for that term:). The R&D department submits to the design engineers a "wish spec list", and I could say the majority of the times the final "production spec list" differs from the original "wish". That is why I stated the "Speciman" that was submitted to the United States Patent and Trademark Office on Dec. 13, 2007 by EESTOR means nothing.
If EESTOR ever commercially produces an EESU I can guarantee the final product spec list will not be the same as the submitted.

What company do you work for Steve321? Competitor to EEStor?

Robert, I think I got (most of) it.

The terminals are used both for input and output.
20A @ 24VDC as output terminals.
Disconnected from that discharge use and switched to the charging configuration.
As input (re-)charging terminals, the output circuitry use would be inactivated.
And, essentially, those terminals directly connected to the EESU capacitor terminals.

Don't think that voltage rise is going to be linear.
Very very quick rise, initially from 0V (or whatever the residual voltage is).
Very limited rise / approaching flat, nearing 3500V (or 5000V).

In any case, not recharged directly (in 90 seconds) from an ordinary household 15 or 20 Amp circuit!

90 seconds is going to require that the "specialized charger" have an embedded (second) EESU which can be slow charged via a wall socket, but provides the kick ass power to supply the entire charge in just 90 seconds.

I wonder if physical EESU module swap wouldn't be better.
But that wouldn't have the same sex appeal of a 90 second recharge, would it.
Even though the "specialized charger" takes, oh, 1/3 hour (20 minutes) using ~15A @ 120VAC, to be ready to provide the next 90 second full phaser blast.

eestorblog wrote:

Steve321 wrote:

nekote,
The company I work for does use the term "wish spec list"...I can't take credit for that term:). The R&D department submits to the design engineers a "wish spec list", and I could say the majority of the times the final "production spec list" differs from the original "wish". That is why I stated the "Speciman" that was submitted to the United States Patent and Trademark Office on Dec. 13, 2007 by EESTOR means nothing.
If EESTOR ever commercially produces an EESU I can guarantee the final product spec list will not be the same as the submitted.

What company do you work for Steve321? Competitor to EEStor?

Steve321 wrote:

eestorblog wrote:

Steve321 wrote:

nekote,
The company I work for does use the term "wish spec list"...I can't take credit for that term:). The R&D department submits to the design engineers a "wish spec list", and I could say the majority of the times the final "production spec list" differs from the original "wish". That is why I stated the "Speciman" that was submitted to the United States Patent and Trademark Office on Dec. 13, 2007 by EESTOR means nothing.
If EESTOR ever commercially produces an EESU I can guarantee the final product spec list will not be the same as the submitted.

What company do you work for Steve321? Competitor to EEStor?

I signed an NDA, can't disclose name of company. The only thing I can say my company designs and manufactures products for military and civilian applications.

what kind of products?

nekote wrote:

Robert, I think I got (most of) it.

The terminals are used both for input and output.
20A @ 24VDC as output terminals.
Disconnected from that discharge use and switched to the charging configuration.
As input (re-)charging terminals, the output circuitry use would be inactivated.
And, essentially, those terminals directly connected to the EESU capacitor terminals.

Yes

nekote wrote:

Don't think that voltage rise is going to be linear.
Very very quick rise, initially from 0V (or whatever the residual voltage is).
Very limited rise / approaching flat, nearing 3500V (or 5000V).

That describes a constant power charge. A constant current charge will provide a linear voltage rise.

Dig back to your basic definitions

Charge on a capacitor

Q = C * V

Definition of current

I = dQ/dt

nekote wrote:

In any case, not recharged directly (in 90 seconds) from an ordinary household 15 or 20 Amp circuit!

Indeed

nekote wrote:

90 seconds is going to require that the "specialized charger" have an embedded (second) EESU which can be slow charged via a wall socket, but provides the kick ass power to supply the entire charge in just 90 seconds.

I wonder if physical EESU module swap wouldn't be better.
But that wouldn't have the same sex appeal of a 90 second recharge, would it.
Even though the "specialized charger" takes, oh, 1/3 hour (20 minutes) using ~15A @ 120VAC, to be ready to provide the next 90 second full phaser blast.

Naw, the fast charge would be reserved for sites that needed to charge many modules quickly, everyone else will just keep a spare.

Robert

eestorblog wrote:

Steve321 wrote:

eestorblog wrote:

Steve321 wrote:

nekote,
The company I work for does use the term "wish spec list"...I can't take credit for that term:). The R&D department submits to the design engineers a "wish spec list", and I could say the majority of the times the final "production spec list" differs from the original "wish". That is why I stated the "Speciman" that was submitted to the United States Patent and Trademark Office on Dec. 13, 2007 by EESTOR means nothing.
If EESTOR ever commercially produces an EESU I can guarantee the final product spec list will not be the same as the submitted.

What company do you work for Steve321? Competitor to EEStor?

I signed an NDA, can't disclose name of company. The only thing I can say my company designs and manufactures products for military and civilian applications.

what kind of products?

Bretspot wrote:

Can someone help explain what they mean by this:
Volume: 9.44 x 10^5 mm^3 (101.6 mm cubed), the cubed part has me confused, since it doesn't seem to add up.

(101.6 mm) x (101.6 mm) x (101.6 mm) is fairly close to 944000 cubic millimeters

As ricinro pointed out, this is basically (4 inches) cubed, or 64 cubic inches.

I was doing some researching and found this:

http://www.repairfaq.org/REPAIR/F_safety.html

And now the 24 Volt limit on the EESU makes sense. If you never expose the 3500+ volts via any externally easily accessible part of your device, it seems to be in the range of allowed devices. (not to mention that 3500+ volts doesn't work with really anything).
Supposedly non-consumer serviceable parts of microwaves go up to 5000 volts.

Daniel R Plante wrote:

For the device described, using the output as the charging input would wildly increase the complexity, cost and failure rate of the electronics attached to the output terminals of every storage device.

Actually it would require only the ability to shut down the switcher. The parts needed for the switcher are already rated for the load. No additional complexity is needed. I can draw the circuit if it's not clear.

Everything else follows from that, no need for extra volume and a single station does the charging.

The big drawback is the peak power draw. If you could actually keep the current constant it would only take about 70s to charge. It does make for a simple scalable charger though. Even limiting the maximum power will get you a fairly quick charge. And you might be able to take advantage of the surge capability to increase the current at the beginning. You'd probably want to add a temperature sensor though.

Robert