[brian_]

It's at least a bit amusing that Uflex didn't both to translate some (but only some) of the terms from Italian to English, and list three characteristics of the communications port ("TCP/IP", "RJ45", and "ETHERNET" as if they are three different communications methods, one for each model.

Something doesn't add up to me, based on the minimal description from Uflex:

• Is is just a pile of capacitors? Then a small range of voltage would not use the capacity effectively.
• Is it fronted by a DC-DC converter? Then the 99% efficiency and "no heat dissipation. No need cooling or ventilation" claims are nonsense.

The manufacturer is Kilowatt Labs, not Uflex. Their website claims a 100% depth of discharge, which is not possible in practical terms (since a fully discharged capacitor is at zero volts), but suggests that the capacitor voltage is taken very low, so the power conditioning must include a DC-to-DC converter.

This is the entirety of the EV section of their Storage Applications page:

Electric Vehicles

Bringing Instant Mobility to the Electric Vehicle Industry.

With a charging time of less than 15 seconds, the Sirius battery enables instant mobility to electric vehicles, putting them at par with a combustion engine car. With an energy density of 115Wh/kg of delivered energy, a cycle life of 15,000 cycles, high temperature tolerance and low cost, Sirius battery enables electric vehicles' attributes to exceed combustion engine cars for the first time.

The Sirius battery can be deployed in all kinds of vehicles, 2 and 3-wheel vehicles, passenger trucks and buses, trains, trams, SUV's, industrial vehicles, and military vehicles.

So a 30 kWh battery would weigh 261 kg... so this isn't a leap forward in energy density by mass; the advantages would be in power density (especially for charging) and cycle life.

I have no idea who they think will be reading this that would think that the number of wheels on a vehicle would change whether or not it can use this type of energy storage.

Self-discharge has always been an issue with capacitors, and this product actually includes a small lithium ion battery to compensate, so it's definitely still an issue:

A charge retention circuit controls a small percentage of embedded Li Ion to supply current to reduce charge leakage and increase self-discharge time to 14 days.

 

[brian_]

This post was just put up on the Aussie EV forum site...
The author is Paul Wilson of Arvio the importer of the Sirius battery in Au

Post by Supercaps » Today, 18:26

Start by reading the patent that was published yesterday. Just for clarification there is no in series dc to dc conversion...

So, they are using only a small fraction of the capacitor energy capacity, by operating them over a narrow voltage range?

Anyone citing a patent should provide the patent number (and of course issuing country); otherwise, it just looks like a bluff, assuming no one will actually look it up.

 

[brian_]

.....the latest post from P Wilson (Arvio)

There are 1200 x 3,000F super capacitors. 2.7V each. 20 in series and 30 in parallel per layer x 2 layers.

...
Bottom line is, they are claiming to have a 3000F supercap the size of an 18650 cell !.
.....how likely is that ?
.....

That's the operating voltage of Eaton's XL60 product, announced in 2016; however, the XL60 cells are much larger than an 18650 - 60 mm in diameter - and have a capacitance of 166 F. A module containing 18 of them (standing vertically in a 3x6 array) is 177 mm high, 420 mm long, and 196 mm high. That's 166 F, not 3,000 F, so the claim here is 20 times greater capacitance in a small fraction of the volume.

Energy storage in a capacitor is 1/2CV**2, so charging a single capacitor of 3,000F would store
0.5*3000*2.7**2
=10,935 J or 3.04 Wh

Then a set of 1200 would store 13,122 kJ or 3645 Wh, matching the 3.7 kWh claim... but would have to be fully discharged to zero volts to extract that energy. Something does not make sense here.

 

[brian_]

2.7V is an ordinary value for a supercap. It does not mean anything in relation to Eaton or any other brand.

I didn't say or even suggest that these were the Eaton product; in fact, the huge size difference confirms that they are not the same. This was a comparison of capacity - a massive improvement on the order of a factor of 100 - as I explicitly stated.

And it is a cap, so discharging is a linear proces, unlike chemical storage.

What doesn't make sense is a claim of capacity that could only be achieved by fully discharging to zero voltage... because, as mentioned above, the relationship of voltage to state of charge is completely unlike an electrochemical cell.

Restoring the critical and omitted context:

Then a set of 1200 would store 13,122 kJ or 3645 Wh, matching the 3.7 kWh claim... but would have to be fully discharged to zero volts to extract that energy. Something does not make sense here.

With no voltage conversion component (as also claimed), an energy store with output dropping to zero is not usable.

 

[brian_]

Thats the point,... They claim it IS a drop in replacement for any 48v battery.
Its normal operating range being 44-54 volts.

Okay, good catch

Energy stored by 1200 3000 F capacitors at 54/20 = 2.7 volts:
1200 * 0.5 * 3000 * 2.7**2 = 13,122 kJ or 3.645 kWh

Energy stored by 1200 3000 F capacitors at 44/20 = 2.2 volts:
1200 * 0.5 * 3000 * 2.2**2 = 8,712 kJ or or 2.42 kWh

Net energy available over operating range of 44 V to 54 V:
13,122 kJ - 8,712 kJ = 4410 kJ or 1.225 kWh

(Yes, I know that can be more elegantly expressed as
1200 * 0.5 * 3000 * (2.7**2 - 2.2**2) = 4410 kJ or 1.225 kWh
but I'm not sure that's as clear)

So, can someone explain either what I have missed in my calculations, or how the other 2.4 kWh of stored energy is supposed to be delivered, once the voltage has dropped to 44 volts? How about why +6/-4 volts is an acceptable change from a nominal 48 volts, in competition with a lithium battery?

 

[brian_]

In the first video they did mention batteries - but it was something about the supercaps not being able to retain charge for a long time so the batteries somehow fixed that

That's the scheme in which a small battery is used to charge the capacitors as necessary to maintain some minimum level to avoid damaging them. It's not meaningful to storage capacity, but the inclusion of electrochemical cells in a system claimed to have none is disturbing.

I wonder - maybe the 3.6 kWh on the box is the actual storage capacity - BUT with it configured as a battery you can only use 1.2 kWh

Then the 3.6 kWh claim is meaningless crap. If someone owes you a hundred dollars and gives you a box containing a hundred dollars, but you can only ever actually get ten bucks out of it, does all the extra money in the box do you any good? Do you feel ripped off?

Which would tie in with lead acid batteries where you can only use a fraction of the capacity
Or even Lithium where you can only use 80%

Even a lead-acid battery can be discharged to the full depth of the rated capacity... it costs in cycle life, but the voltage at the end of discharge is still close to the nominal and usable. At even 80% depth of discharge, this "48 volt drop-in replacement" which must be charged to 54 volts to be fully charged is down to 24 volts; that's not useful.

 

[brian_]

...".And the latest reply from Arvio commenting on the Patent " battery" reference... ????????

Post by Supercaps » Today, 17:22

Yes the patent covers this. Patents are normally written as broadly as possible to prevent copying methods by other parties. This is why the words “in some embodiments” and “can” are used. There are no lithium ion electrochemical cells in the super capacitor modules which are being used. Good to see you doing your research. Have you worked out how it’s done yet?...

Suggesting the patent is bit of commercial deception ?

Claiming that the design is covered by a patent then sending that "Have you worked out how it’s done yet?" response from Supercaps about the patent would be suitable for someone attempting to insult the recipient as much as possible.

If I were a potential buyer, I would quite bluntly tell them where to stuff their patents, and to get back to me when they have decided to communicate professionally and prove their claims.

Yes, patents are often filed for any design which can be pushed through the patent processes (which is just about anything now, since patentability no longer requires that the idea be novel, non-obvious, or even workable) and might at any time be used. It's not deceptive, it's just covering all the bases (even possible product names are trademarked although they might be built)... until the company says that the product is as described in patent and then says "gotcha, it's really not".

 

[brian_]

Minor point Brian, but he didnt say there was no dc/dc conversion......he actually said there is no "in series". dc/dc conversion !

In parallel would make no sense. Weasel words don't give me a lot of faith.

Now that may be nothing ,..or it may distract from the fact that there could be some cell level conversion trickery,.
That previous photo with the blue supercap bank showed a lot of cell level electronics.

My guess is that's the cell monitoring, and charging (from electrochemical cells!) at extremely low voltage.

I suppose it's also possible that the entire unit is reconfigured to half as many cell in parallel and twice as many in series at the low end of the cell voltage range... but then why not just say that?

With regards to the voltage range, a typical 48v lithium pack (13 S of 18650s ), would typically have a full capacity range of 39-55volts ( 3v - 4.2v per cell) .

Good point, but that full range is not typically used, and the lithium voltage range is much narrower for a very large fraction of the full capacity... and vehicle manufacturers routinely state both a nominal (full voltage range) capacity and a usable capacity.

This reminded me of a previous "ultracap" discussion...
Anybody remember the "fastcharge" 1000 hp drag bike thread ?..
http://www.diyelectriccar.com/forums/showthread.php?t=178345&highlight=1000+drag+bike
What happened to that project ?... Their blog is gone and the site is "dusty"

I skimmed through that discussion... yes, very similar.

 

[brian_]

OK,.. More feedback from Arvio..

Post by Supercaps » Today, 01:45

Just to clarify a few things. The super capacitor in the picture is one of the range of super capacitors, not the one in the 3.55kWh unit. Secondly the calculations are correct except for the micro farad typo. The missing piece of the calculations is understanding of the technique used to extract almost all of the energy from the capacitors from 54VDC down to 44Vdc when in series without a series DC to DC converter. Yes there are electronics involved. The electronics perform high speed balancing between the parallel cell groups. This is the IP of the product. You can learn about this by reading the patent. The real test is at the terminals, which can easily be shown to deliver the energy stated. The unit can be shown opened up to anyone interested in person to have no electrochemical batteries and proven with a colomb meter to be what is stated. Still haven’t had anyone from this thread come to visit. Doors are always open. Nothing to hide......

So, rather than DC-DC conversion "in series" with the capacitor output, they are presumably pumping the remaining charge out of some cells in a normally parallel group to the rest, probably in stages.

Man, it would have been a lot easier to have just said that.

Someone with the patience to read their patent while mentally deleting all of the non-applicable parts, and keeping in mind that patents are intended to describe rather than explain, can see if that seems reasonable.

 

[brian_]

Not graphene this time but a superelectrolyte and stainless steel with a special sauce:

http://www.greencarcongress.com/2018/03/20180319-rr.html

Could be the next one with 180Wh/kg.

Big name is involved: RR as in jet engines and luxury cars.

The Rolls-Royce engine and automotive companies have been unrelated for decades... but yes, Rolls-Royce is a major and very capable manufacturer of turbine engines for various applications. That's a good thing due to the technical resources which will be available to the project, but the purpose is still to "explore the potential" of the technology.

 

[brian_]

We seem to be going in circles.

Interesting
So 8.5% at 44v and 95% at 53v

Just don't see how you do that with Supercaps unless you set the "zero" at 40v
So if 2.7v is full then "zero" would be 1.9 volts

OR...if they really have figured out how to get most of the energy out (8.5% remaining). Whilst holding the pack voltage minimum at 44v , then it only needs to go up to 55.5v (2.77 per cap) to hold the full 3.55 kWh. ???

Right - that's how capacitors work, and what I've been saying since post #2 and first quantified in post #13. Either most of the energy is not coming out, or the caps are going down to a much lower voltage (1.9 volts if they're all in the same state). There is no other option in the real world.

I wonder - maybe the 3.6 kWh on the box is the actual storage capacity - BUT with it configured as a battery you can only use 1.2 kWh

Maybe that is how they do it - it's actually a 12 kWh pack and they are only using the top 3.5 kWhs

I think that it is much more likely that they are only using the top 1.2kWh and that the 3.5kWh is a true but irrelevant capacity

Okay, but in the statement quoted in post #26 the distributor explicitly said this is not the case.

So we are back to the issue that They would have to use some form of voltage boost that is not dc/dc as we understand it ?

It's just not DC-to-DC at the place (point in the power flow) where we expect it... which they call "in series", because we would expect the output of the capacitors to go through the DC-to-DC converter to reach the load.

As I suggested earlier:

So, rather than DC-DC conversion "in series" with the capacitor output, they are presumably pumping the remaining charge out of some cells in a normally parallel group to the rest, probably in stages.

So the cells which get nearly fully discharged are taken down to much lower (well below 1.9 volts) voltage by DC-to-DC converters which add that energy to the remaining cells, which only get down to 2.2 volts (for a 44 volt series bank). They call this "high speed balancing between the parallel cell groups", although I think to most people familiar with complex batteries "balancing" means the very opposite: equalizing state of charge, not deliberately shifting charge to a selected group of cells.

Thoughts on this likely implementation, and the cost, particularly in efficiency? Is it worthwhile compared to running the entire output through a DC-to-DC inverter (given that either scheme would only be necessary once the caps drop to something like 2.2 V each)?

 

[brian_]

Paul W at Arvio has now posted a video of what he claims is a "recharge test of a 3000F supercapacitor"...
https://youtu.be/m_hyyQ5-d0E
It shows one of their devices charging from 0v to 2.7 v in approx 30 secs...

I didn't bother watching the whole thing or listening to any of it, but text near the beginning notes that the voltage jumps to 2.7 almost immediately. That's presumably what misled Karter2, and it is also inconsistent with a capacitor. I assume that he is charging through a control circuit which throttles the charge rate - the voltmeter is seeing 2.7 volts, but that can't be across a capacitor being charged.

Why is nothing from these people straightforward and credible?

 

[brian_]

Just watched the video

He has an average of 5.5 amps for 15 minutes - 900 seconds - 4950 coulombs

Not the full 8100 coulombs - but the way he "averaged" it looked a bit suss

Suspect?

I see your comment on the video; it should be interesting to see the response.

 

[brian_]

Arvio uploaded a discharge test on one of the 3000F "supercaps"...
https://youtu.be/aQD8hk2llN0
Looks more like a LTO battery than ever !

I agree... that certainly doesn't look like a capacitor discharge curve!

 

[brian_]

... So the 3.55kWh pack would actually be a 7 kWh pack that they were only using 3.55 kWh

But again, the distributor (the manufacturer is nowhere to be seen in this discussions) has repeatedly claimed that they are using all of the energy in the capacitors, not just partially discharging them.