400C drag racing cells! ( Li-IOn Capacitor !)

[Doctorbass]

John Metric recently posted a prototype of 240C cells for drag racing!


That one is 240C continuous, 400C burst. 800Amps

I have some prototype 200C and 240C continuous cells I have talked with some suppliers about. They want a minimum $30,000 order however.

http://www.jmenergy.co.jp/pdf/ULTIMO Brocure-en.pdf

I want some!

let start a group buy!! :lol:

The current top drag racing pack look like this one

all made of 100C RC lipo

Doc

Doc

 

[neptronix]

13whrs/kg though.
Lead acid is what.. 33whrs/kg?

Wouldn't a >100whrs/kg cell with 100C output make a lot more sense? such as those high end RC Lipos..

 

[liveforphysics]

It has a huge C-rate, but such a low energy density it looks like a Nano-tech still beats it for power density.

 

[TheBeastie]

I don't like it when you guys post cell specs from a one dimensional point of view, if I was in charge of this forum I would have you banned for poor representation/discussion on total cost of ownership of cells.
If where going to only ever look at batteries from a single discharge point of view why not just buy non-rechargeable batteries? Oh thats right total cost of ownership etc.. Yet when it comes to you guys and numbers its all compared by a single discharge.

According to the sites data here you can expect at least 800,000 cycles on each cell.. http://www.jmenergy.co.jp/en/product_whats.html

So if you take 13Wh/kg and times it by 800,000 you get 10,400,000 Wh of total energy expected for the life time of the 1kg worth of cells thats over 10million Whrs of energy.
Your beloved HK lipo will give you 145Wh/Kg times by 300cycles will give you 43,500 Wh of total energy expected from the cells life time.

 

[liveforphysics]

The context is drag racing. Cycling is irrelevant for the application.

If the context is commuting, the energy density is comically low. A 43g modern 18650 that will last the life of the vehicle can deliver what 1kg of cells store.

 

[neptronix]

It's just that your pack will just be about fourteen times larger and heavier than a RC Lipo pack, that's all.

Let me use basic multiplication and division for the sheer sake of humor:
You can fit about 30AH of 60C 48v RC lipo into an ebike triangle right now.

150whrs/kg vs 13whrs/kg of the same capacity and size would mean..

Your RC Lipo pack can output 1800A and has 30AH.
Your 'li-ion capacitor pack' can output 840A and is 2.1AH.

If you are racing in the 'quarter foot' category instead of the 'quarter mile' category, You'd still lose the race :lol:

 

[Doctorbass]

Yeah, just like Luke said, for drag racing, what you need is a battery that have just the right amount of energy for one run and to keep in the SOC where voltage dont sag too much. All excedent energy is useless and add weight!

typically it is easy to estimate!

a drag racing run is about 7-12sec but let's keep 12 sec.... and this is equivalent to 3600/12 = 300.

That mean the C rate your cell need for a 12sec run is 300C and just a bit more energy than the run require.

Guys like John Metric use about a Megawatt of power and for 12 sec that's 3.3kWh

YEs.. they consume about 3.3kWh i 12 sec !

Doc

 

[TheBeastie]

I don't really see it that way for exclusive use, I think marrying these cells to high capacity low C rate cells like Samsung 35E 18650s would work great.
Let the cap cells do all the hard high discharge work on take off and then allow the low C rate cells fill in on the cruising, as discussed time and time again any high discharging on any regular li-ion cell kills its total cycles life time.

 

[neptronix]

That will not negate the problem. They'll run out of capacity hilariously fast + the whole pack will sag like a MFer still.

Another math problem. This one involves calculus and i won't get into it... other than to say that it won't work like you think it will :lol:

 

[TheBeastie]

That will not negate the problem. They'll run out of capacity hilariously fast + the whole pack will sag like a MFer still.

Another math problem. This one involves calculus and i won't get into it... other than to say that it won't work like you think it will :lol:

This point of view has been brought up many times but I just can't see how, even if you include internal resistances etc, and also for the fact this same type setup has been studied in detail here and that its conclusions show it does work. http://web.ing.puc.cl/~power/paperspdf/dixon/42a.pdf

Also come across articles like this from time to time...Where its being used in race cars.
http://www.economist.com/news/science-and-technology/21606715-new-sort-storage-device-gives-lithium-ion-batteries-run-their?fsrc=scn/tw/te/pe/firstoneuptodrive
For instead of batteries, the Toyota TS040 hybrid (pictured above) has a supercapacitor.
The main beneficiary will be transport. Toyota is already incorporating lessons from the TS040 into its road cars. The Yaris Hybrid-R, a concept car, uses a supercapacitor to provide quick bursts of power. There is industry gossip that the firm is also working with BMW on a sports car that will use supercapacitors. PSA Peugeot Citroën has started fitting supercapacitors to some of its cars as part of its stop-start fuel-saving system, as this permits faster start-ups when the traffic lights turn green.

Public transport, too, is benefiting. Maxwell Technologies, an American supercapacitor-maker, reckons more than 20,000 hybrid buses use the devices to provide bursts of power during acceleration. They are particularly popular in China.

 

[neptronix]

It's simple electrical properties.
Assuming that everything discharges properly..

You've got 10% 400C supercapacitor, 90% 1C battery, right?

400 / 90 = ~4C battery pack.

Your 250whr/kg ends up getting reduced to about 225whrs/kg.

To do some more precise math, let's think of it like this.
You've got 50% 400C supercapacitor, 50% 1C battery, yes?

13whrs/kg + 250whrs/kg / 2 = 131whrs/kg.

400C + 1C / 2 = 200.5C.

Okay, you've combined an incredibly light cell with the heaviest lithium cell ever produced, and you've got decent output. But your overall cost is going to be probably 10 times greater for the whole pack versus a pack that's:

150whrs/kg & 100C peak output ( best case with RC Lipo ).

You'd need about a 33% supercap / 67% super light lithium mixture in order to get land you in the high end RC lipo range. Then, your cost would be probably only 5 times what RC lipo is..

Then you also have to solve the issue where the high capacity cell runs at a different voltage than the low capacity cells. You'd want two battery management systems.

You'd also need a pretty large pack..

Is it feasible? yeah. Does it make any economic sense? hell no, unless you've got $100,000 to spend on a battery.

 

[Punx0r]

For Heaven's sake. "DRAG RACING"

Anyway, are these not simply super capacitors like those that are produced by Maxwell? Energy density seems to be about the same at ~15WH/kg. I don't know where "lithium ion" comes into things?

The point about high C-rate not necessarily making a battery best for high performance is a great one

 

[okashira]

LMAO. I thought you were trolling us with a jack in the box cup

 

[TheBeastie]

Anyway, are these not simply super capacitors like those that are produced by Maxwell? Energy density seems to be about the same at ~15WH/kg. I don't know where "lithium ion" comes into things?

The point about high C-rate not necessarily making a battery best for high performance is a great one

Looking around the Maxwell PDFs for caps that can give 15wh/kg but couldn't find any, got a link?
Best I found was http://www.maxwell.com/images/documents/K2_2_85V_DS_3000619EN_3_.pdf
Which says 7.6 wh/kg, Also annoyingly the Maxwell PDFs don't seem to mention wh/l, I think considering these jap caps are rectangular in shape they should have a good lead on the maxwell cylinder caps.

I though I saw someone say the jap caps want a min 30k order, how many do you get for that? Then an accurate compassion can be made against the Maxwell caps in cost vs wh/kg and maybe a bit in cost vs wh/l.

I did find these Taiyo Yuden 270 Farad 3.8v caps for around $80 each, not as impressive compared to the 3300f ULTIMO caps but its still cool to see real LICs ready for sale off the shelf. Its nice to see something move from just some dubious tech article of new claims in energy/power density to something we can actually buy even if its pretty expensive to begin with.
http://au.mouser.com/ProductDetail/Taiyo-Yuden/LIC2540R3R8277/?qs=%2fha2pyFaduiChGsCdHBpc9S9EFkhnLuKj%252b8hmQf5R33%2fA8QKf01QgwZ2fe9XvKzY

This guy did a kickstarter campaign (url below) to take these caps and shove them AA AAA cell sized canisters as a super fast 10,000+ cycle rechargeable 1.5v cells. I guess selling point to most folk would be for those that have extreme battery recharge Impatience, despite the high price.

For me rather its a case that I do suffer a lot from "battery cell waste guilt", so far I have struggled to see anyone suffer from environmental destruction via battery cell waste guilt considering the responses to this type of technology.
https://www.kickstarter.com/projects/shawnpwest/30-second-charging-rechargeable-battery/description
When looking at this I expected if it was a scam (since its well past a year ago) it would say something in the main page or 'updates' page but there is nothing. Then after googling around the web I find a few accusations about it being scam, then I finally click on the 'comments' part in kickstart and see all the complaints... Just as many at kickstarter along the lines of "kickstarter is also enjoying the money we gave this scammer"...
https://www.kickstarter.com/projects/shawnpwest/30-second-charging-rechargeable-battery/comments

 

[okashira]

Not impressive really once I opened the datasheet.
Here, I put where a Samsung 30Q NCA 18650 cell lies on their graph:
(I assume 30A burst or 100W per cell, which should be reasonable, IMHO.)
This is a perfect example why batteries should not be compared by "C" rate. "C rate" is useless for anything except determining run time (and at 400C, these caps are for a 9 second lifetime. lol)

Near the same power density for an order of magnitude more energy density by weight. So a Samsung 30Q at 10C nears one of these caps at 400C for power density.
Probably looks even worse by volume.
Even Model S cells can do > 1000W/kg...

 

[liveforphysics]

You're drastically better off adding something like modern 18650s, even if the goal is just to act as a power buffer for a low-c pack.

I don't really see it that way for exclusive use, I think marrying these cells to high capacity low C rate cells like Samsung 35E 18650s would work great.
Let the cap cells do all the hard high discharge work on take off and then allow the low C rate cells fill in on the cruising, as discussed time and time again any high discharging on any regular li-ion cell kills its total cycles life time.

 

[Punx0r]

Looking around the Maxwell PDFs for caps that can give 15wh/kg but couldn't find any, got a link?

Sorry, it was a sloppy reference. Memory suggested somewhere between 5 and 10 Wh/kg for the Maxwell caps from a previous search and the Wikipedia page for supercaps said "up to 15Wh/kg".

 

[cwah]

At 13wh/kg... the math can be as simple as...
- Power density = 13wh * 400 C = 5200W/kg.

In comparison, the nanotech can still provide 50% more output power at 7500W/kg:
http://www.hobbyking.com/hobbyking/store/__53725__Turnigy_nano_tech_A_SPEC_G2_5000mah_6S_65_130C_Lipo_Pack_UK_Warehouse_.html

So nanotech will still be lighter!


Or just get the classical A123 at 4000W/kg:
http://www.a123systems.com/prismatic-cell-ahp14.htm

A bit heavier but already famous for its quality!

So not worth it.

 

[Punx0r]

So, is John Metric missing the trick, or are we?

 

[Hillhater]

John is smart enough to know which way to go.
I don't read that he has committed to go with the Ultracaps ,..do you ?

PS :- Toyota, who probably have better resources and inside contacts than most, have just dropped the Ultracapacitor packs from their LM Endurance racing hybrids in favor of a Li based battery technology ( ? Don't know which cells though)
They felt they were definitely at a disadvantage compared to Porsche and Audi who have been using Li cells.
F1 teams, who really do need the max recharge (regen) capability as well as high discharge ability, are pretty much all on Li cells....very good ones !

 

[jmetric]

I looked at these. I met with the sales department to discuss supply. Where it fell apart is the little asterisk items.
The wise folks on here already did the math, calculate out the actual kW/liter, they stopped supplying the loose pouches, they only come in the plastic cases now. They do not stack anywhere near as dense as the pouch cell batteries.

Also, These "batteries", when sitting by themselves at 40degC (a hot summer day in Houston), have an extraordinarily high self discharge rate, much like a cross between a battery and a capacitor and they have a minimum voltage requirement that must be maintained or else they fail, which means you have to have this battery pack plugged in at all times. I am very leary of that. I do not practice plug it in and forget.
When installed in a UPS system where there is constant top off power available and a really professional BMS system this appears to not be a problem. But when you don't race for a week or a month or sometimes over winter, you can't be having these plugged in for months.

lastly, price was not effective yet. I have the price list, these didn't even come close until 250,000 units. and they wont sell you the loose 3300uF pouches.

 

[liveforphysics]

Agreed John.

They don't win for power density over hobby packs, they have pitiful energy density, and if they have that great of self discharge they likely will be puffed soon anyway.

 

[Hillhater]

But i notice you do have some new 100/200C lipo pouches available now John ?
Are these significantly better than your previous cells ?

 

[jmetric]

Yes, you can buy singles for testing....