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Old 07-31-2007, 03:19 PM   #91
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I had one EP pack from the carpet nationals. I did not race it for ~3 months after the race. The pack ran very strong, took a good charge (about 4800 mah @7A). The IBs *in the past* have not held up like this. I don't see how the EP self discharge is worse than the IB cells. I had a similar situation with IBs from Cleveland, didn't try them until March. They were pukey.

This is my experience, and I only relay it because I have yet to see a problem with EP cells . Maybe they do self discharge, but there seems to be no ill effects from it.

Not trying to cause an arguement, just wanted to get this out there. I'm just in a special situation because of the large gaps in my racing in the last year.
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Old 07-31-2007, 03:28 PM   #92
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Originally Posted by razzor View Post
Only hassle with the EP/Ib debate has been that the EP cells were supposed to be cheaper but with them getting a better rep and good results from matchers the price has increased to equal the IB.
i have not seen this to be true. even like for like packs same voltage and same runtime, the ep are cheaper. i guess if you are looking for ep with the same runtime and voltage as the top of the line IB, then I can see that they are the same price. The EP cells just don't have the voltage int he 1.24+ range. so there are less EP cells in a case, and therefore sell for more.
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Old 07-31-2007, 03:37 PM   #93
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I understand what your getting at about reliability and you want cells to last for an entire season but I think it will be hard to accomplish this with any of the newer high performance cells.

Since most competitive racers want the best and freshest cells at every major race the current battery situation has been very good for this as the batches of cells stay very consistent which measn there is more then enough high voltage cells for everyone at a major race. So a racer racing at 4 major races per season he should buy 1 to 2 fresh pack per race. So that amounts to 8 packs maximum per season which is not that bad.

I don't like to talk to much about the EP cells as many will accuse me of protecting my business since we import and sell IB cells but I have gotten samples of EP cells in the past and I have yet to see that it's way more reliable than the IB cell. There maybe less cells that selfshort but I have seen a drop in runtime and voltage with an increase IR just by cycling them. Like I said in one of my earlier posts I think some of the companies pushing EP cells is based on money savings when purchasing the cells and the fact that less cells selfshort which equates to more profit for that company.

I think IB has been doing a good job lately at improving reliability while being able to keep the voltage as high as it has been and the IR as low as possible.
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Old 07-31-2007, 03:38 PM   #94
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ithe problem is that these cells I have had don't last very long at all. I believe that the EP's are great cells, just a hair short on power compared to the IB's........but on the flipside - i would sacrifice initial power for longevity of cells. This way my cells I buy for Vegas can last me through the winter for club racing.
Just curious as to what you mean by "... don't last very long at all." How many charges/discharges are you getting per pack?

Since I'm new to EP, I'm trying to figure out what battery I'm going to get. I'm leaning towards the IB4200WC = $$$.

Thanks for the info.
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Old 07-31-2007, 03:45 PM   #95
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Originally Posted by robk View Post
I had one EP pack from the carpet nationals. I did not race it for ~3 months after the race. The pack ran very strong, took a good charge (about 4800 mah @7A). The IBs *in the past* have not held up like this. I don't see how the EP self discharge is worse than the IB cells. I had a similar situation with IBs from Cleveland, didn't try them until March. They were pukey.

This is my experience, and I only relay it because I have yet to see a problem with EP cells . Maybe they do self discharge, but there seems to be no ill effects from it.

Not trying to cause an arguement, just wanted to get this out there. I'm just in a special situation because of the large gaps in my racing in the last year.

What we call selfdischarge is the ability of the cell to hold it's residual voltage or storage charge. The EP M3 cells seem to selfdischarge faster than the IB cells. I did mention in my post that the EP cells seem not affected as much when they go under 1 volt. To be honest it's still to early to tell if the latest lots of IB cells will be much more reliable but so far from early test results it seems very encourageing. Just the fact that the cell selfdischarges 35% slower than the previous batches makes me think that storage will be greatly improved. Time will tell.
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Old 07-31-2007, 04:57 PM   #96
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Danny,

In a major event do you prefer your team guys to run cells fresh off the matcher or do you have them put a few practive runs on them first?

In other words what is your method to get the most out of your IB's?

Travis
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Old 07-31-2007, 05:19 PM   #97
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Normally we will run 2 packs at a major race. We will use it a few times in practice and then race it in the heats and main. At a race like Cleveland and the Snowbirds where you race every 6 hours one pack is all that is needed.
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Old 07-31-2007, 07:18 PM   #98
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Originally Posted by rmdhawaii View Post
Just curious as to what you mean by "... don't last very long at all." How many charges/discharges are you getting per pack?

Since I'm new to EP, I'm trying to figure out what battery I'm going to get. I'm leaning towards the IB4200WC = $$$.

Thanks for the info.

I should have stated that differently. The amazing performance of the IB's I have had degrades over time - faster than I would like. I would say that my packs are at top notch for about a month of racing, still plenty good at the 2month range, and then they become you feel the degredation (i.e. flatness, not as punchy) around the 3-4 month range.


This is racing every weekend too.....
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Old 07-31-2007, 07:57 PM   #99
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[QUOTE=Danny/SMC;3537126]

I don't like to talk to much about the EP cells as many will accuse me of protecting my business since we import and sell IB cells but I have gotten samples of EP cells in the past and I have yet to see that it's way more reliable than the IB cell. There maybe less cells that selfshort but I have seen a drop in runtime and voltage with an increase IR just by cycling them. Like I said in one of my earlier posts I think some of the companies pushing EP cells is based on money savings when purchasing the cells and the fact that less cells selfshort which equates to more profit for that company.



They might not be WAY more reliable....but they are more reliable.
Yes there are a lot less cells that self short. When you buy ep's the chances of getting a pack with a dead cell is way less than buying ib's.

You say you've seen a drop in run time and voltage as you cycle your test cells..............This is true with all cells. If not your team guys could run the same cells all year.
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Old 07-31-2007, 08:15 PM   #100
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This is why I don't like to give info on the web because some of you will want to argue about everything.

Let me explain what I mean by they drop as I cycle them. When I took EP samples versus IB cells and cycle them the IBs get better for the first few cycles on the Turbomatchers and then stay the same. The EP cells looked good on the first few cycles and then started to drop off little by little when cycling them.

When someone gets one of our packs with a new cell that is shorted we simply replace it. I believe that the newest lots will have less issues so hopefully we don't have to worry about replacing cells as much.
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Old 07-31-2007, 08:17 PM   #101
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Well, if EPs are anything like IPs then that to me is good enough. I have 3sets of IBs and 3 sets of IPs that were bought at the sametime, and run the same amount of times. The IBs have started to flattened out and started to vent more at the six month mark. The IPs are now just starting to show signs of degrading. I had bought all these batteries last year in October for our regional. And since now I am on a budget, they need to last and still have good voltage. With the IBs, I have seen them get fickle with temperatures. FYI, I charge and discharge all my batteries the same.
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Old 07-31-2007, 08:25 PM   #102
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You shouldn't treat all your cells the same. In my tests we have seen the IB cells get 15-20 degrees hotter using the same peak detect when compared to IPs so what works for one brand maybe not as good for the others. We typically use .02 peak detect for the entire pack and the IP guys seem to run .05.
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Old 08-01-2007, 08:23 AM   #103
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Originally Posted by Danny/SMC View Post
You shouldn't treat all your cells the same. In my tests we have seen the IB cells get 15-20 degrees hotter using the same peak detect when compared to IPs so what works for one brand maybe not as good for the others. We typically use .02 peak detect for the entire pack and the IP guys seem to run .05.

Danny, Do you use .02 for 1/12 scale stock?
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Old 08-01-2007, 09:25 AM   #104
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Originally Posted by Danny/SMC View Post
Normally we will run 2 packs at a major race. We will use it a few times in practice and then race it in the heats and main. At a race like Cleveland and the Snowbirds where you race every 6 hours one pack is all that is needed.
I had it wrong all this time I have been to Cleveland a few times and would race two sometime three class and would buy four pack for each class all that waste of money, I though that the packs need at least 24 hrs rest before they are good to race again, now I know different I will only buy two packs from now on.
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Old 08-01-2007, 09:31 AM   #105
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Danny, that is fine for your purpose of testing inside a building that is possibly air conditioned. However, I use 0 peak since I am out in the heat and the temp probe on the Ice chargers are off by at most 10 degrees from my Raytek temp gun. If I treat my batteries the same then I know how to gauge them for my use. Everybody has their own way of gauging how long their batteries last by their own methods for their particular use. Since my use is in a 12th scale in the south Texas heat, that is how I go about telling if a battery is worthy of continuing to buying. Not only that, they sit in the back of my truck in my Ofna travel bag in a Racers Edge Battery case under a toneau cover another 2 hours or so till i get home. So, if a battery can withstand that type of treatment and still provide me the power I need after 6 or seven months then they are worth buying again if i can still get them. And that was money well spent on good batteries. Fyi, the back of my truck gets to about 120 degrees at times.

Last edited by CarlosG.; 08-01-2007 at 09:50 AM.
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