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Old 12-23-2004, 08:33 PM   #136
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Quote:
Originally posted by Jon Kerr
A 7th cell won't give any more run time. If anything it'll shorten it because of the extra amp draw the motor would be pulling.
Well in that case then lets all just run five cell mod
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Old 12-23-2004, 08:36 PM   #137
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I can see that 5cells would give you more runtime but wouldnt they be a tad slow for us all?
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Old 12-23-2004, 08:42 PM   #138
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actually it would not give any more or less runtime... it would allow the motor to take more power..

cycle a 6 cells pack.. you runtime will be what it shows on the lables if they are new. or at least close..

now cycle a 4 cell pack. the numbers will still read the same.. exept the average pack voltage will read less, but then u just average it over 4 cells not 6...

so 3 4 5 6 cells does not gain anything more then speed...
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Old 12-23-2004, 08:50 PM   #139
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All,

Don't get too exicted about GP3700's yet. They are a different size then the 3300 cell. The cell is still catorigized as Sub-C, but the size of the can is slightly larger. This may become an issue because of the rules and regulations of such organizations like ROAR. As you know, GP had make the 'shorty' version of the current GP cell to abide by ROAR regulations.

I've talked to the the engineers, they commented that it is very difficult to squeeze more capacity in the same size cell... I'm very interested to see if runtime, voltage or IR will take a negative hit.
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Old 12-24-2004, 04:08 AM   #140
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Heard the 3700`s are gona have a lower IR than the 3300`s..

yep,

there gona be faster.....
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Old 12-24-2004, 08:50 AM   #141
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My source told me they are the same size and fit into the current rules.
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Old 12-24-2004, 09:01 AM   #142
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Umm I don't know about that, John. A GP representative wrote this to me yesterday:

"As far as the 3700's we do not have an exact release date at this time. I do not know if you are aware, but these cells are a different size than the 3300's. It is still a Sub C, but the size of the can is slightly larger. This might be an issue because of the rules and regulations in the races, so I want to make sure all my customers are aware. That is the only information I have regarding this cell at this time."

Guess we'll just have to wait and see...

Merry Christmas!
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Old 12-24-2004, 09:49 AM   #143
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Quote:
Originally posted by burbs
actually it would not give any more or less runtime... it would allow the motor to take more power..

cycle a 6 cells pack.. you runtime will be what it shows on the lables if they are new. or at least close..

now cycle a 4 cell pack. the numbers will still read the same.. exept the average pack voltage will read less, but then u just average it over 4 cells not 6...

so 3 4 5 6 cells does not gain anything more then speed...
That's not true at all. The more cells in the battery pack, the more amp draw the motor will pull thus greatly affecting runtime...the more cells, the greater the power but the lower the runtime since the motor will pull juice faster.
Take a look at 4 cell 1/12 scale racing. They run 4 cells with 8 minute mains. Take the same car and put 6 cells in it and you will not be able to get 8 minutes out of it.
Testing a pack on a charger and testing a pack when hooked up to a motor are 2 different things (when comparing runtime). When on a charger the amp draw is constant, but that's not the case when hooked up to a motor.
When I cycle my packs on my GFX, I discharge at 30 amps and, for example, I get 400 seconds of run time. Now when that same pack is in my car, I know my stock motor does not pull 30 amps (no stock motor does unless it's assembled incorrectly or you crash causing a power surge) so I WILL get more than 400 seconds of runtime!
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Old 12-24-2004, 12:38 PM   #144
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Ko

Not quite correct. The only difference for current draw between 4 cell and 6 cell is the extra current required to move the extra 2 cells around. Up until a few years ago, most 12ths were 6 cell.

Chris.
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Old 12-24-2004, 01:13 PM   #145
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think about it... the more voltage you apply to an electric motor the higher the amp draw, but you also get more rpm. You can test that by free-wheeling on a turbo GFX or 35 at 3 volts and then at 5 volts etc. the amp draw goes up. You can also prove this by doing dyno runs with a turbo dyno etc. go from 5 to 7 volts and usually the amp draw will go up.

The biggest issue however is that the motors are not going to be able to take the voltage increase. In mod touring you are virtually frying them as we speak. Even in some 19 classes the motors are getting over 200 degrees.

Back when 7 cell offroad was popular we didn't run 7 or 8 turns. Also the batteries had higher resistance so it didn't kill the motor as bad.

$.02
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Old 12-24-2004, 04:43 PM   #146
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They will be out around March, and the will probably cost more.
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Old 12-25-2004, 12:58 AM   #147
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According to the GP engineer I talked with, the new cells are 0.2mm larger in diameter and a few grams heavier. My brother, a local matcher, is already testing 12 cells. Initial number seems ok, 450+ with 1.16+ at 30A. Proceesed cells go up to 1.17+. IR is similar to 3300.
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Old 12-25-2004, 01:17 AM   #148
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Quote:
They run 4 cells with 8 minute mains. Take the same car and put 6 cells in it and you will not be able to get 8 minutes out of it.
that is why we adjust our gearing to make time... you can not expect to run a 4 cell gearing with 6 cells...
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Old 12-25-2004, 02:02 AM   #149
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Both Gary and Mars are correct, guys. Gary and I have both been in contact with our vendors and reps and they're all saying the same thing: the cells is slightly larger.

I'm also not vibing that they're gonna be that great for stock racing. We'll be getting samples in January to test out. I believe they will be as Mars said: 1.17+ with 2.5+ IRs--nothing amazing.

Where they'll be great is for modified racing all around.

That's okay--I believe we'll have a trick up our sleeve for stock racing this coming year.
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Old 12-25-2004, 06:04 AM   #150
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Quote:
Originally posted by Mars
According to the GP engineer I talked with, the new cells are 0.2mm larger in diameter and a few grams heavier. My brother, a local matcher, is already testing 12 cells. Initial number seems ok, 450+ with 1.16+ at 30A. Proceesed cells go up to 1.17+. IR is similar to 3300.
Can you post what you have from the 12 GP3700 cells after process??
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