# High power cells, A123, Saft, Headway!



## Yabert (Feb 7, 2010)

Hi

I currently search good cells for high power application. 
When I started my project, I would use the A123 26650, but at this moment their cells are rare, the price is high and the assembly is a bit complicated.

So, I’m interested by Headway 38120P. He is easy to build pack, but these cells seem have a relatively poor power. I will wait the test for their cells performed by Crodriver. 

Since I start to watch Saft lifepo4 technologies. The Saft VL25Fe seems are really good cells. More powerful than A123 and in a large and easy to assemble format.
Someone had the chance to test this cell?

Also, if there have other high power cell you can proposed.


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## CroDriver (Jan 8, 2009)

I have already tested Headway cells. I don't have a graph but they seem to sag to 2.0V at 200Amp.

Do you know if the saft cell is available for purchasing and what's the price?


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## frodus (Apr 12, 2008)

then design your pack with more in parallel. a cell that is being asked to deliver that much power continuously is not in a well designed pack. If you need 2000A out of the pack, then you should stay as close to 1C as possible, despite what A123, Headway, Saft say. IMHO, stay closer to the continuous rating of the cell, not the peak.

200A on an 8Ah cell is pretty good, and not many applications ever require that much current for more than a few seconds.


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## Yabert (Feb 7, 2010)

Hi Crodriver.
Cell sag to 2v after how many time? Is it the same result performed by *electrabishi?*




> Starting with cell temps at 28*C they held above 2.0V for 2 min 32 seconds. Now I was watching the voltages closely so I could terminate the test when one hit 2.0V. I was not watching the temp and upon completion they were at 85*C. A little stress on them that time. But 2 min 32 sec at 200 amps is somewhere around 6.67 AH.


So, thanks for this information. Do you have test the internal impendence? 
Also, Is it possible for you to perform some other discharge test because there are a lot of information on net about headway 10Ah cell, but few about high power 8Ah cell.

For me 200 Amps per cell is enough, but if the graph below is right, I am a bit disappointed about the voltage sag on poor curve at only 24A.

Concerning Saft battery I’m currently in quotation process for small order. But for the moment, that would be like difficult to have. Watch the first answer: “These cells are not available for purchase only element / separated. We can sell them in assembled according to your definition of the final product”

I will be back later if there have development.. 



Well, somebody had the chance to have A123 32113 cells? Supposed to be 4.6Ah and “uses the new Ultra electrode design, offering even higher power than the traditional ANR26650M1”


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## CroDriver (Jan 8, 2009)

Mike (electrabishi) has posted some test results which don't include the voltage(drop) figures. He just told how many amps at a given temperature he could pull. 

I saw the voltage drop instantly. My results probably defer from frodus's results because the ambient temperature at his tests was 15*C higher

Temperature affects these cells quite much.

Btw. You can't ask us for everything, use the search function and do some homework 



Yabert said:


> Hi Crodriver.
> Cell sag to 2v after how many time? Is it the same result performed by *electrabishi?*
> 
> 
> ...


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## MN Driver (Sep 29, 2009)

Yabert, you said high power application but didn't state your application. If it's an EV, are you drag racing? If it's a vehicle of any type that isn't being used for drag racing I don't see how you would go through this much energy so fast to where even an A123 which is likely cheaper than these SAFT cells doesn't cut it. The 25Ah cylindrical size is great though. 1200 amps from a 25Ah cell 48C as a continuous rating and 88C for 2 seconds, WOW! I've only seen something close to this with R/C LiPo where it was 45C continuous with 90C burst but very expensive and the power leads didn't look like they could take the 396 burst amperage. I'm still not sure what applications could use 45C continuous. I keep on thinking vehicular engine starting applications or other heavy motor starting applications just to get something moving with this type of current. ...even one of the EndlessSphere guys managed to use 10Ah Headways to cold start a diesel truck though, I have my doubts it could do it a few hundred times but it was interesting to read about.


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## Bowser330 (Jun 15, 2008)

More high power cells on the market sounds good to me...more options, no one can complain about that.


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## BMI/LiFeTech (Aug 12, 2009)

MN Driver said:


> I keep on thinking vehicular engine starting applications or other heavy motor starting applications just to get something moving with this type of current. ...even one of the EndlessSphere guys managed to use 10Ah Headways to cold start a diesel truck though, I have my doubts it could do it a few hundred times but it was interesting to read about.


We have just released our new car booster starting packs which use our LiFePO4 cells. These packs would want to start a couple of hundred times (at least) since we provide 2 years warranty on these units which have inbuilt adjustable LED torch, flashing red hazard LED's, FM radio and USB power socket built in for charging mobile devices. They come with a mains charger as well as cigarette lighter socket for auto charging.

The discharge curve of the cells we use in these packs is much flatter than the discharge curve of the Headway cells. I will try to post the independent test report with the cell discharge curves.


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## Yabert (Feb 7, 2010)

That seem interesting...


> The discharge curve of the cells we use in these packs is much flatter than the discharge curve of the Headway cells. I will try to post the independent test report with the cell discharge curves.


Please post it and give information about availability of this cells. Thanks.


Well, it seem have some choise in large format high power Lifepo4 cells

-A123 32113
-Headway 38120P
-Lifebatt 38120 XPS-1P
-Saft VL25Fe

Do you know some other?


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## MN Driver (Sep 29, 2009)

There is always this page that has links to more specsheets that you can shake a stick at.
http://liionbms.com/php/cells.php

I tried to look for cells outside of the standard ones used here for a very size-sensitive application before I realized that size wasn't such an issue as someone made a bad conversion between US and metric with a prototype. They do have various cells listed as power cells. ...although usually they are near the size of the A123s but you might find something that is a good choice. :shrug:


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## BMI/LiFeTech (Aug 12, 2009)

Yabert said:


> That seem interesting...
> 
> 
> Please post it and give information about availability of this cells. Thanks.


The car engine start pack above uses our less powerful 15Ah X2E cells. 
The smaller X1P cells have far higher discharge rate capability (up to 35C peak). Very few people require this kind of discharge rate for your average road going EV which is why our packs which use our high energy X2E cells (10C continuous 15C peak discharge) are by far the most popular.
More info on the quality of our cells can be found at this current thread over on the ES forum- http://endless-sphere.com/forums/viewtopic.php?f=14&t=17361

Discharge curves for both cells can be found below-
(I often get told by customers how nice my curves are!)


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## BMI/LiFeTech (Aug 12, 2009)

Yabert said:


> That seem interesting...
> 
> 
> Please post it and give information about availability of this cells. Thanks.
> ...


To prevent any confusion it is best to refer to the cell as a LiFeTech XPS cell and not LiFeBatt since LiFebatt Inc. (LiFeBatt USA) is an entirely separate company and they do not manufacture or supply our cells. LiFeBatt prismatic cells are manufactured by a different company.
We have many EV's under test at the present time by some of the major auto makers in the USA and our main service agent for the US is located in Oklahoma.


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## RIPPERTON (Jan 26, 2010)

(hey Armin)

check these videos

Saft rocket propulsion systems
1: nail
2: overcharge after 1 hour 20 minutes

http://www.youtube.com/watch?v=WFea3l1RtEI


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## BMI/LiFeTech (Aug 12, 2009)

RIPPERTON said:


> (hey Armin)
> 
> check these videos
> 
> ...


Hey Daniel,
With flames like that shooting out of your battery it is not a really good look as you are driving down the street in your EV!
Clearly not a LiFePO4 battery.


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## MN Driver (Sep 29, 2009)

BMI/LiFeTech said:


> Hey Daniel,
> With flames like that shooting out of your battery it is not a really good look as you are driving down the street in your EV!
> Clearly not a LiFePO4 battery.


I'm not at my computer to see the fire video linked above but LiFePO4 is not immune to fire and will start on fire with an overcharge as well. It takes quite the overcharge but this was done at about 8C into a cell will violently vent flame once it passes 20 volts under severe overcharge. Hard to reproduce that in a real world situation but it can happen.


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## RIPPERTON (Jan 26, 2010)

BMI/LiFeTech said:


> Hey Daniel,
> With flames like that shooting out of your battery it is not a really good look as you are driving down the street in your EV!
> Clearly not a LiFePO4 battery.


Il just perch a blonde on the back of my R1 and no one will notice the flames.
But realistically I would have to be ambushed by a nut with a nail gun.


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## RIPPERTON (Jan 26, 2010)

MN Driver said:


> I'm not at my computer to see the fire video linked above but LiFePO4 is not immune to fire and will start on fire with an overcharge as well. It takes quite the overcharge but this was done at about 8C into a cell will violently vent flame once it passes 20 volts under severe overcharge. Hard to reproduce that in a real world situation but it can happen.


Exactly, It wouldnt be the batteries fault, it would be extreme user error
likewise the nail


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## MN Driver (Sep 29, 2009)

Here's the video of the Headway cell fire video that I mentioned after 21 volts and some added heat. Once it starts, they are on their own and don't need help to get any worse. It gets interesting at the 3 minute mark.

http://www.youtube.com/watch?v=wkJM8MZkFKU

Every chemistry is when overcharged. Lead-acid's hydrogen will explode, LiPo explodes, LiFePO4 evidently can have violent flame, prismatic NiMh was just demonstrated here that with an overcharge caused an erupted cell that included fire in the process. The more energy and power density there is, the more heat a cell can create when bad things happen. ...just like gasoline, condensed energy in any form has lots of potential, just don't light the match.


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## Yabert (Feb 7, 2010)

> To prevent any confusion it is best to refer to the cell as a LiFeTech XPS cell and not LiFeBatt since LiFebatt Inc. (LiFeBatt USA) is an entirely separate company and they do not manufacture or supply our cells


Well, I had a quotation from lifebatt... so what is the best way to have quotation from Lifetech?


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## BMI/LiFeTech (Aug 12, 2009)

Yabert said:


> Well, I had a quotation from lifebatt... so what is the best way to have quotation from Lifetech?


Your quotation from Lifebatt was obviously for a different product since they don't sell our product. Their product is now from a different manufacturer, lower C ratings, prismatic cells compared to our cylindical cells, etc.
So I am a bit confused as to how can you compare two quotes from different companies for entirely different products?


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## Yabert (Feb 7, 2010)

Hi

I don't need to compare..... I only need to know how I can have a quotation for your cylindrical cells and what is the availability of this one.

Thanks


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## BMI/LiFeTech (Aug 12, 2009)

Yabert said:


> Hi
> 
> I don't need to compare..... I only need to know how I can have a quotation for your cylindrical cells and what is the availability of this one.
> 
> Thanks


Hi Yabert,
Please email me directly at [email protected] with your requirements.
I apologise in advance for any delays in getting back to you since I am at present away interstate visiting some boating customers regarding the batteries for two electric patrol boats which we are providing.


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## eva-michael (Apr 13, 2010)

MN Driver said:


> I'm not at my computer to see the fire video linked above but LiFePO4 is not immune to fire and will start on fire with an overcharge as well. It takes quite the overcharge but this was done at about 8C into a cell will violently vent flame once it passes 20 volts under severe overcharge. Hard to reproduce that in a real world situation but it can happen.


If the temperture go too high or some linkages(wires, soldering part or some things) dont capable enough to load the big current. First come hot and then it may start a burn......dont make light of connection!


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## helluvaengineer96 (Oct 8, 2010)

MN... Great link! 


MN Driver said:


> There is always this page that has links to more specsheets that you can shake a stick at.
> http://liionbms.com/php/cells.php
> 
> I tried to look for cells outside of the standard ones used here for a very size-sensitive application before I realized that size wasn't such an issue as someone made a bad conversion between US and metric with a prototype. They do have various cells listed as power cells. ...although usually they are near the size of the A123s but you might find something that is a good choice. :shrug:


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## webfootguy (Sep 11, 2007)

More info on the Saft cells at: http://www.phostechlithium.com/documents/T13-Deveney10thElectrochemicalPowerSources.pdf


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## rashomon (Feb 9, 2011)

I was involved in developing a lithium-ion motorcycle start battery (lead-acid replacement) for a motorcycle OEM. The issue was that the initial peak load for 100ms or so on the first crank was quite high, and the voltage could easily drop low enough to reset the ECU. Let me just say that 32113s at 1P substantially outperformed 26650s at 3P. The difference was most noticeable at temperatures below 0C.


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