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Old 01-10-2008, 05:08 PM   #61
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Since I referenced a link to an unfair comparison, I'll make it up by posting my own data.

Attached is some cycle life data. Kokam and Enerland were tasked to produce the same cell in their 20C chemistry. They were given dimensional constraints as well.
Enerland submitted a custom cell 5mm thick, x 35mm wide x 35mm tall. It averaged a hair over 400 mAh in capacity.
Kokam submitted a custom cell 5mm thick, x 34mm wide x 35mm tall. It averaged about 375mAh.

Both were subject to a 30+C pulse discharge with a 2.8V/cell cutoff with the same load. Since the Kokam cell was lower capacity, the discharge C rate was slightly higher than the Enerland cell.

The new Enerland cell started off great - easily trouncing the Kokam cell. However, the Enerland cell faded very fast. It could not handle a 2.8V/cell cutoff even though the spec sheet was 2.7V/cell.
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Old 01-10-2008, 05:10 PM   #62
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Sorry, the previous graph may be hard to read.
Basically, the 5 cells that drop off in 200 cycles are Enerland cells. The ones that continue to 1500 complete cycles are Kokam.
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Old 01-10-2008, 05:12 PM   #63
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So how robust are the Kokam cells?
The next set of testing was nearly the same, except now the cutoff voltage was reduced to an extremely low 2.2V/cell - well below the recommended limit.
900 cycles with very little degredation.
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Old 01-10-2008, 05:15 PM   #64
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Believe it or not, there are cell manufacturers out there with more power than Enerland with the cyle life of Kokam. They just haven't hit the RC car market yet.
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Old 01-10-2008, 05:16 PM   #65
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Quote:
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I apologize, my mistake. I didn't read closely enough.
I'll make it up to you though. I'll post some more comparison testing.
I missed that too

I was really wondering how that was.......

My cut off kicks in, its 6.3V is what my volt meter says after I hit the LVC
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Old 01-10-2008, 05:17 PM   #66
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Quote:
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Believe it or not, there are cell manufacturers out there with more power than Enerland with the cyle life of Kokam. They just haven't hit the RC car market yet.
NEU energy are looking nice, its 25, or 30 C in a hard case
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Old 01-11-2008, 12:14 PM   #67
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Linger, I believe you are argueing in a way that will lead to no where.

First: I am not defending any lipo maker.

Second: I know Kokam is Kokam are my compliments to them for beeing the "motor" of the evolution of lipo cells for rc use since one day mr. Hong arrived at a forum and asked "what are your needs for this type of cells" at that time lipos were achiving 2~3C discharge rate. Today they do 30C, by that time I remeber two makers in competition and today they are dozens.

But I have to tell you that the way you discharge the cells does not reflect how they are suposed to be used.

The makers tell us do not bring the voltage down from 3v/cell as they will suffer and loose capacity. Do not use them over a certain % of the rated capacity as we will short the cells live. We all know that, and we all know that if you bring, just one time, the cell under that voltage you can lose that cell and drop in the garbage.

So what is the point of graphing the live of cells with a use that we should not do to our cells?

If your job is to convience us that Kokam is better than everybody else, than I understand, but if it is not...
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Old 01-11-2008, 07:56 PM   #68
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Also, the graphs were really lame....

I was looking at it, how can you compare a flight power 3300 3S pack, and a Kokam 4000 4S pack?

Comparing apples to oranges doesnt prove anything, and then I wanted graphs of the actual orion pack, and the TrakPower pack, not just a enerland, and Kokam, atleast have the same specs, 2s packs with the same MAH...
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Old 01-11-2008, 10:14 PM   #69
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Originally Posted by BlackedOutREVO View Post
Also, the graphs were really lame....

I was looking at it, how can you compare a flight power 3300 3S pack, and a Kokam 4000 4S pack?

Comparing apples to oranges doesnt prove anything, and then I wanted graphs of the actual orion pack, and the TrakPower pack, not just a enerland, and Kokam, atleast have the same specs, 2s packs with the same MAH...
maybe you guys should run some test and display some graphs.
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Old 01-12-2008, 02:47 AM   #70
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Kokam

Just goto Kokam's web site

Orion 3600's ROCK the 10.5 and the 13.5 class

I will do some testing of the Core 5000's very soon.
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Old 01-12-2008, 12:53 PM   #71
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maybe you guys should run some test and display some graphs.
I was going to buy a eagle tree data logger because it would be fun to have for my BL trucks, but for the price, I bought a bunch of new parts, and a high end motor (Motor was 215 bucks, and I bought $127 I believe it was in parts..... So im broke now....)

I need to talk a friend into buying one
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Old 01-12-2008, 12:58 PM   #72
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testing is too over rated simply because there are people so biased that graphs or track tests wouldn't matter. At the club races when people are getting beat consistently by another racer and they ask what motor/batteries/car they are using then maybe they will start to see what packs may or maynot be better. Just my $0.02
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Old 01-12-2008, 01:10 PM   #73
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testing is too over rated simply because there are people so biased that graphs or track tests wouldn't matter. At the club races when people are getting beat consistently by another racer and they ask what motor/batteries/car they are using then maybe they will start to see what packs may or maynot be better. Just my $0.02
Yeah I know...... But still a comparison of someone at there track running one pack, and then putting the other pack in and running it, I would like to know what the graphs look like

But yes, if your the guy that wins every time, I dont think a different brand lipo will make you loose...
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Old 01-12-2008, 03:15 PM   #74
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Yeah I know...... But still a comparison of someone at there track running one pack, and then putting the other pack in and running it, I would like to know what the graphs look like

But yes, if your the guy that wins every time, I dont think a different brand lipo will make you loose...
without graphs being involved the only lipo that seems to have me wanting to try it other than my orion packs is the Core lipo. The track power hasn't really turned my head. If anything I'd rate it the same as the Orion as far as on the track goes......again the only reason why I haven't tried the Core is because of the different plugs on the two batteries. Call me lazy but I don't want to have to switch connections between two packs.
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Old 01-12-2008, 03:38 PM   #75
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without graphs being involved the only lipo that seems to have me wanting to try it other than my orion packs is the Core lipo. The track power hasn't really turned my head. If anything I'd rate it the same as the Orion as far as on the track goes......again the only reason why I haven't tried the Core is because of the different plugs on the two batteries. Call me lazy but I don't want to have to switch connections between two packs.
You could put bullets on the core pack....

It comes with deans right? Just solder some female bullets and it would be fine.......
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