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EFRA decision. 5 cells -1350gr

EFRA decision. 5 cells -1350gr

Old 01-08-2007, 06:08 AM
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... and the batts are getting hot 'cause your now taking the old 6cell amps out of 5cells... hmmm
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Old 01-08-2007, 06:33 AM
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Originally Posted by TryHard
... and the batts are getting hot 'cause your now taking the old 6cell amps out of 5cells... hmmm
The batteries are wired in series. So each cells see the same amp draw no matter how many batteries there are.

The batts are the same temp as before. Last summer My packs could come off the track well over 150 deg F running 6 cell with a 7 turn.
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Old 01-08-2007, 08:42 AM
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Originally Posted by AdrianM
The batteries are wired in series. So each cells see the same amp draw no matter how many batteries there are.

The batts are the same temp as before. Last summer My packs could come off the track well over 150 deg F running 6 cell with a 7 turn.
This is assuming that the amp draw from the motor is the same with 5 as with 6 cells, which it isn't.

And since the elevation in temperature is directly related to the amp draw, thanks to the Joule effect, it makes sense that things get hotter with 5 cells.
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Old 01-08-2007, 09:20 AM
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No offence Adrian, but can you explain then why the batteries at the Jap nationals (on 4cell admitadly) were getting killed in one run?

Don't get me wrong, I'm not against 5cell... mainly cause someone saw the sense to actually lower the weight limit at the same time. Should make for some good racing for the coming season...
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Old 01-08-2007, 09:32 AM
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Originally Posted by AdrianM
The batteries are wired in series. So each cells see the same amp draw no matter how many batteries there are.

The batts are the same temp as before. Last summer My packs could come off the track well over 150 deg F running 6 cell with a 7 turn.

This is the first time i read something from Adrian i dont agree

Theoratically amp draw as nothing number of cells.

The thing is, with 6 cells we had to much power, so most racers left a lot of juice at the end of the 5min.

With 5 cell, because motors are understressed, we can gear higher and push the timing a litle further, hence biger amp draw.

The same priciple aplies to 4 cell in japan.

My .2 cents
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Old 01-08-2007, 09:47 AM
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Originally Posted by Itchy
This is the first time i read something from Adrian i dont agree

Theoratically amp draw as nothing number of cells.

The thing is, with 6 cells we had to much power, so most racers left a lot of juice at the end of the 5min.

With 5 cell, because motors are understressed, we can gear higher and push the timing a litle further, hence biger amp draw.

The same priciple aplies to 4 cell in japan.

My .2 cents
Well, idd, you're right... one more problem is the use of even hotter motors to get the most power I guess. Look at 1/12th, 6 cells I think there's no issue getting 8min out of a batt. 4 cells, everyone goes with hotter motors so the amps go up and sometimes 8 minutes is difficult.
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Old 01-08-2007, 10:29 AM
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Originally Posted by TRF415boy
This is assuming that the amp draw from the motor is the same with 5 as with 6 cells, which it isn't.

And since the elevation in temperature is directly related to the amp draw, thanks to the Joule effect, it makes sense that things get hotter with 5 cells.
If you are on pace in 6 cell mod you are close to dumping. I only have 10-20 sec left im my pack after a run. That means I am drawing ~45A average.

When I have tested 5 cell I still finish a run with 10-20 sec left in the cells. That means I am drawing ~45A average...the same as with 6 cell.

If you are have 1000mah in your cells after a 6 cell mod run you have to be at least a lap or two off the leaders pace or there are no really fast drivers at your track.
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Old 01-08-2007, 10:54 AM
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Originally Posted by TryHard
No offence Adrian, but can you explain then why the batteries at the Jap nationals (on 4cell admitadly) were getting killed in one run?
Its simple really...

4 cells dump harder than 6 cell because you started out with less voltage to begin with. Both 4 and 6 cell packs get discharged to the same point but a dumped 4 cell will move your car a lot slower than a dumped 6 cell pack.

As far as batteries getting killed...there are some ugly truths here that no one want to acknowledge but here we go...

IB4200 are incredibly fast cells but they are also extremely fragile. 4 or 5 cell racing dosent kill batteries any faster than 6 cell. High level mod racing kills cells no matter what voltage you run. If you dont believe me when you come back from your next big race running 6 cell mod discharge you packs on a Much More CTX-D. I gaurantee that at least one cell will be ruined (dump a minute early, high IR) in almost every 6 cell pack you own...even the new ones with just a run or two on them.
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Old 01-08-2007, 11:08 AM
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Would Gp cells be more durable with the mod discharge being consider ?
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Old 01-08-2007, 11:48 AM
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Originally Posted by Wild Cherry
Would Gp cells be more durable with the mod discharge being consider ?
I am not sure but I do know that they are not competative with the latest IB cells so there is not much point in running them.

Keep in mind this is a Mod issue. The guys that run Stock and 19T are not as hard on the batteries so if taken care of properly they will last in Stock and 19T.
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Old 01-08-2007, 01:56 PM
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If we are at a point where mod racing kills cells that quickly, why would anyone be interested in running mod, whether 4, 5 or 6 cell?

Dave
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Old 01-08-2007, 01:57 PM
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Originally Posted by dave
If we are at a point where mod racing kills cells that quickly, why would anyone be interested in running mod, whether 4, 5 or 6 cell?

Dave
good point dave
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Old 01-08-2007, 02:13 PM
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Originally Posted by AdrianM
If you are on pace in 6 cell mod you are close to dumping. I only have 10-20 sec left im my pack after a run. That means I am drawing ~45A average.

When I have tested 5 cell I still finish a run with 10-20 sec left in the cells. That means I am drawing ~45A average...the same as with 6 cell.

If you are have 1000mah in your cells after a 6 cell mod run you have to be at least a lap or two off the leaders pace or there are no really fast drivers at your track.
You are right Adrian.
If a racer is dumping his batts around minute 5-6 with 6 cells there´s no diference in amp draw.
Were i live (Portugal) we had the 12turn limit, so its a diferent case.

i guess i always agree with you after all
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Old 01-08-2007, 09:05 PM
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Originally Posted by AdrianM

If you are have 1000mah in your cells after a 6 cell mod run you have to be at least a lap or two off the leaders pace or there are no really fast drivers at your track.
??? didnt someone mentioned before that during last year's RROC, Marc Rheinard had some 600mah or more left in his batts after each run? or did i read wrongly?
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Old 01-08-2007, 09:50 PM
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Originally Posted by Kyew
??? didnt someone mentioned before that during last year's RROC, Marc Rheinard had some 600mah or more left in his batts after each run? or did i read wrongly?
Yes, that was when the IB4200's were new. Now its a year later and we have learned how you use ALL of the capacity.

If you give a modified racer a bigger battery he will figure out a way to use all of it in 5 min....thats a fact
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