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Supercapacitor storage bank ?

13636 Views 71 Replies 9 Participants Last post by  somecallmetim
Sorry if this product has been raised before, i searched and nothing came up.
Kilowattlabs Sirius Supercapacitor storage "battery "
Several of the other forums ..Solar, EV, tech , etc...are having some debates over the Sirius product which claims to be the first Supercapacitor based storage device for use with Solar systems, utility storage, EVs, RVs etc etc
They claim it can replace any current Lead ,AGM, or Lithium, battery function.
Infact the list of claims are extensive, not least being rapid charge/discharge, 99% efficiency, million cycle life with no capacity reduction, totally fire safe (non combustable materials) , and $1/Wh price point.
Note they are initially offering 3.5kWh and 7.1 kWh , units with other sizes and voltages to follow.
Obviously if any of this is true, then storage has truely advanced instantly, but as many of us realise, these claims go beyond any current proven Supercap performance abilities.....hence why there is hot discussion raging.
Some of you may already be involved in those discussions on other forums , but my reason for raising it here is to rais awareness to either help prove/disprove the validity of this device such that we either can avoid it or benefit from its technology.
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To be fair, that video predates my revelation that you can buy unlabelled LTO cells in capacitor-style cases. And we don't know if Paul Wilson has read that yet.

The device Paul waves around between 7:23 and 7:45 in that video
looks remarkably like the LTO cell shown here:
which is unlabelled apart from a polarity stripe.
You must have missed where they are claiming:
1 million cycles at 100% DOD with negligible capacity fade
a 45 year calendar life
operation without degradation at 85 °C
can be charged in less than 30 seconds without affecting cycle life
no risk of thermal runaway


And at 9:40 in this video, Paul Wilson implies they are completely non-toxic by claiming they are compostable, containing only carbon and paper, wrapped in aluminium.

Every one of those claims would be ludicrous if they admitted it was a lithium ion battery (possibly with a few supercaps added for show).

But as a "Capacitor Module" those claims begin to seem plausible.
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I saw all that
But I still don't see how a company could hope to make any money doing this

If they have a huge demand - then people will open them up and see that they have been lied to
No. When you open them up, you see what looks like unlabelled capacitors. You can't tell they are LTOs by looking at them. Nor can you easily tell they are LTOs by their voltage vs SoC curves, provided you stay within the 44 V to 54 V limits specified by the manufacturer, because LTOs happen to be fairly linear in that region, particularly at the 2C rate.

The main reasons I am fairly confident they are LTOs are:
1. I have read extensively about the current state of the art in supercapacitors, and we're nowhere-near this energy density, even in the lab, let alone mass production. And the chance that some lone genius could leapfrog everyone else by about 10 years is negligible.
2. LTO cells are commercially available that look exactly like the "capacitors" in the Kilowatt Labs unit and they have exactly* the required voltage, internal resistance, energy capacity, weight, dimensions, linear region of voltage vs charge curve, and (as we've seen most recently) flammable electrolyte. * Within 5%. [Edit: And low enough cost]

Now we're waiting for Arvio to release a 1C voltage versus charge curve that goes outside of the linear region for LTOs.

At this stage, I'm assuming good faith on their part.
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But you can tell from the voltage charge curve for a supercap - the slope on that curve is equal to the capacitance

We have been told the capacitance -
if these are batteries then they will have an effective capacitance of about four times that
Sure. But then they could just say they got the capacitance wrong and they're actually better capacitors than they thought! :eek:

So isolating one "capacitor" and doing a voltage/current curve will show what is happenning
Yes. But it has to go outside of the region where LTOs are linear. That's what I challenged them to do 4 days ago, and that's what we're still waiting for.
The energy stored in a capacitor is not linear with voltage as it (sort of) is with batteries.

Energy = Capacitance * Voltage * Voltage / 2

So at double the voltage you have 4x as much energy. At 4x the voltage you have 16x as much energy.

It does actually make sense that the voltage skyrockets immediately under very little current flow, and that by the time you drain it even to half voltage, most of the energy is long gone.
This would only be relevant if the charge tests used constant power. They don't. Some are constant voltage (where the device's internal resistance limits the current), others are constant current. With constant current, voltage increases linearly with time for a capacitor.

But even if it was relevant: When you transpose the above equation to give the voltage as a function of the energy, you get: Voltage = sqrt(2 x Energy). Sure, that starts off steeper than it ends, but it is a very smooth and rounded sort of curve. The curves for this device have a very sharp knee in them at around 1.8 to 2.0 volts.
I don't think that's true.

As you add energy into the capacitor, voltage increases as per the formula.
Yes. But constant current doesn't correspond to constant energy per time, it corresponds to constant charge per time. And, for a capacitor, voltage is charge divided by capacitance and energy is charge times voltage. So constant current means energy is going up as the square of time. And since voltage goes up as the square root of energy, voltage goes up linearly with time.

It's important when something is bullshit, that the reasons you debunk it aren't bullshit too.
Yes. Absolutely. So please, don't take my word for it. Look this up elsewhere, to understand where you're going wrong.

Evidence is clear they're LTOs, nothing to see here.
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