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Old 06-16-2004, 08:19 AM   #136
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Old 06-16-2004, 08:40 AM   #137
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Quote:
Originally posted by ProMaX
(...)
"RDS:
Race Discharge Simulation is a testing process that simulates actual race conditions."

It's on the FAQ page, maybe I don't get it right? It says it's simulating a race discharge to weed out the weak cells. Isn't that what Jack is talking about? Isn't that better than 35A discharging? or 40A or 50A??

http://www.team-orion.ch/products/batteries.asp


p.s.
I think I'll stick with my 20A matched GP3300's they perform good enough for me!!
Promax,

It may simulate race conditions but I've seen very strange things.

When i got my first SMC packs I got a brand new T35GFX at the same time. I asked Danny what the parameters were for comparing values on the label with values on the GFX.
I tried that and to my surprise, the runtime was within 1 second of the label and the average voltage was spot on on 5 packs.

The first race with those packs was amazing. Only 3 guys made 13 laps on that track and I was one of them. The other guys were also using SMC packs at the time.

A couple of months later a friend of mine bought new packs from Orion and their labels had amazing numbers (1.183 and 420 discharge). I was impressed. Everybody was...

But he said that the car didn't feel the same.
With his permission I tried a cycle with the exact same parameters I used on mine.
The results were 1.158 and 353 sec discharge.

It seems to me that RDS may have some flaws, especially when that simulation gives poor results on the track. Linear discharge at 30 seems to produce much better packs from SMC.

I could give you more examples how some packs of 2nd generation GP matched at 20A by an european matcher are worthless when compared to SMC in particular and to 30A packs in general.

What I mean is, if SMC feels ok to release 35A it may happen (it just may happen) that they know what they area doing. RACERS (not NASA scientists) would be well advised to trust SMC on this regard.

Some of you may think is a marketing driven need, but if I try one and see a difference I wont really care what enlightened minds (or inquiring minds) tell me. I want that extra second!!!

I know I will, They never failed me, and dealing with SMC and Danny in particular is a pleasure.
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Old 06-16-2004, 09:04 AM   #138
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Going to higher amp matching is a good thing as long as it reflects what's going on at the race track. The matching process should be as abusive on the cells as your 7 turn modified touring car on carpet. This will filter out the weak and marginal cells more effectively. I see 2 mains reasons for matchers to move to higher amp draws:

1) If you are a large matcher like SMC and you can shave 30 seconds off matching times you save huge money. You can have fewer matchers to do the same work with less maintenance.

2) 35 amp matching is closer to what's going on in modified racing at the extremes (again 7 turn touring on carpet).

Let's say you can dump your pack in 5.5 minutes, that's 330 seconds. If your pack was matched at 35 amps and has a run time of 400 seconds your race conditions show you pulling greater than 35 amps on average.

If racers can continue to dump ever increasing capacity cells in ~5 minutes we need to up the matching current to mimic what's happenning on the race track. When 40 amp matchers are available matching companies will likely move to those just like they are moving to 35 amp now.

BTW, if you think the new SMC packs and the matching procedure are bogus, try a pack. Don't complain about stuff you haven't run or at least tested. I'll buy from any company that has a good product and makes me faster.
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Old 06-17-2004, 09:05 AM   #139
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So, when exactly will the new cells be avaliable to the general public? I am going to the stock nats in July and was planning to buy new batteries for this event. But if the new cells will be available I really would like to get them.
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Old 06-17-2004, 09:53 AM   #140
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i ve read through some of the thread bt not all.
i understand what some people are saying about pushing the cells so much bt i understand that smc have done devopment to see how/if they r damaging them.
this isnt really a prob for me.
bt wot i want to now is how do we compare 35 amp av to 30 av?
i.e
i have a peak powerflow gp.specs are
av;1.195 and runtime;415s
so at 35 amp a pack of smc
av;1.165 and runtime;345s.

how would i tell weather the smc were good or not?
we have no charts or comparisons to give us a clue as to weather its a good pack or not.
will smc have charts conversions from 20,30 and 35 amp discharge?
thanks
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Old 06-17-2004, 10:03 AM   #141
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trf racer: Coverting runtime is fairly easy. You multiply the runtime by the discharge rate then you divide that number by the rate you want to get info.

Example: 420 x 30 = 12600 divide 35 = 360.

Voltage is very hard to convert because it depends on the cells Internal Resistance. A high voltage cell can have .012 drop and a lower voltage cell may have .018 drop from 30 to 35 amps.


As far as to comparing your Peak numbers to SMC numbers that will be very hard to do. I don't know why but Orion/Peak seem to be using a different cutoff to get their cell info. Last time I checked a pack it was .02 lower in voltage and 25 seconds less in runtime on our equipment.
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Old 06-17-2004, 12:01 PM   #142
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Quote:
Originally posted by Danny/SMC
Last time I checked a pack it was .02 lower in voltage and 25 seconds less in runtime on our equipment.
Did I hear "lower discharge current" anyone?

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Old 06-17-2004, 12:46 PM   #143
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Quote:
Originally posted by Danny/SMC
trf racer: Coverting runtime is fairly easy. You multiply the runtime by the discharge rate then you divide that number by the rate you want to get info.

Example: 420 x 30 = 12600 divide 35 = 360.

Voltage is very hard to convert because it depends on the cells Internal Resistance. A high voltage cell can have .012 drop and a lower voltage cell may have .018 drop from 30 to 35 amps.


As far as to comparing your Peak numbers to SMC numbers that will be very hard to do. I don't know why but Orion/Peak seem to be using a different cutoff to get their cell info. Last time I checked a pack it was .02 lower in voltage and 25 seconds less in runtime on our equipment.
ok thank you.i didnt no there was a conversion for run time.
i understand what u mean about voltage,as the ir keeps changing from cycle to cycle the voltage would to write?this means that voltage would be to inconsistant to properly calculate?
i dont know about the cu-off voltage bt the matching system variably discharge amp through the cycle but it averages out to 30 amp.
this program is called race discharge system [rds]
it must fluctuate between 25-35 amp discharge.or even 20-40 amp discharge.i dont know but it does vary the discharge amp and averaes to 30 amp.
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Old 06-17-2004, 07:14 PM   #144
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There is too much fudge factor when using variable discharge matching. To be able to compare cells to other cells its best to use fixed paramaters


charge rate 6amps
constant discharge rate 30amps or 35amps

To do race simulated discharge rates is nearly impossible. With 1000s of track and drivers with different driving styles how can a computer simulate "track" discharge rates?
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Old 06-18-2004, 12:24 AM   #145
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Default battery chargers

Ok you guys you have talked the inside of a ducks bum out about charging and discharging batteries. But can anyone tell me is the new futaba cdr5000 a good charger or not. Thank you
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Old 06-18-2004, 02:22 AM   #146
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Quote:
Originally posted by Joel Lagace

To do race simulated discharge rates is nearly impossible. With 1000s of track and drivers with different driving styles how can a computer simulate "track" discharge rates?
How about a 2 or 3s sequence duplicated during the discharge, with a 30 (or even 35A) discharge? The sequance would have lower constant periods, and then a few peaks at 80A or 100A...

Just an idea. Obviously you cannot simulate a whole track with a discharger.

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Old 06-18-2004, 07:33 AM   #147
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Quote:
Originally posted by Safe SX
Ok you guys you have talked the inside of a ducks bum out about charging and discharging batteries. But can anyone tell me is the new futaba cdr5000 a good charger or not. Thank you
why not look at the futaba charger thread to see what people think.
we are allowed to talk even if it is out of a ducks bum,as long as its on topic.

its impossible to do rds because gearing,timing,car,course layout and more have got to be considered.
wot i think tho is meant by rds is varable.
as races vary in current drain.
in other words its not fixed dicharge.
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Old 06-20-2004, 01:31 PM   #148
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WOW! congrats eric anderson for taking the 12th mod win at the kimbrough 400 on sunday! good job bro! guess those 35 amp packs run well on the track huh? ahhahaahahah
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Old 06-21-2004, 07:51 AM   #149
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Joel Legace: There is too much fudge factor when using variable discharge matching. To be able to compare cells to other cells its best to use fixed paramaters...


That is a mouthful! With this statement i would like to ask a question for discussion sake. Since when did a parameter that is "off the chart" become a viable parameter? Im referring to the 5000 second runout that is the "standard" with almost all matching companies. I understand that Trinity made it the norm years ago, and the industry continues to follow/use it. My question is, why? Basically all a battery matcher does is "dyno" cells. Just as a motor dyno runs a motor for a period of time, to determine usable data. It runs the motor no more, no less, to determine the information based on chartable parameters. Actually, heat/repetition, ruins the results of a motors dyno run. Why not make a Turbomatcher do the same thing? No current cell for competitive racing would ever be used for a full 5000 seconds, so why is it a parameter for cell labeling? I understand that using the 5000 runout shows you what the cell can do to 5.4 volts (whatever the cutoff voltage is set too)... but, we never run our cars to that point... matter of fact, we avoid it! I guess it just seems to me, that setting a time, like 500 seconds, places the cells tested on an actual readable/comprable discharge curve. The T-35 still gives you the runtime to the cutoff, so you would still have the runtime in seconds at the set amperage for discharge. Some companies have done this in the past, which some have said to "inflate" the numbers. There really is no inflation, it just tells you what the cell's voltage is at the cutoff. You would still be able to see if one cell was better than another at the end of the 500 seconds... not only would the cell labels show this, but also graphs printed out from the Turbomatcher. The discharge curve could be compared to other cells, and actually be on a "scale" for "computation". If a parameter is out of possible range for the cell to ever reach, can it really be used as a guideline for computation? "Well, IF it could run 5000 seconds, this is what it would be." I dont want if, i want to know what i have in "X" seconds at "X" amp rate. We run 300 seconds for both stock and mod. Make the cutoff 500 seconds to be able to cover both modified and stock class. The rest is runtime we lose to the resistors of a T-35 . God knows we have plenty of runtime in todays packs. I know it is hard to think of things differently, we are a species that loves comfort, both in mind and being. But, we have round rubber tires today, because someone decided square wheels cut from stone didnt roll too well. I guess i posted this for the higher beings to reply and educate us "why" things are done as they are.

(P.S. Dont give me that its because of "cell memory" either... NiMh is nowhere NEAR as sensitive to that as NiCd was.)

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Old 06-21-2004, 10:17 AM   #150
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DaveW: There would be no difference between 500 and 5000 because they both exceed the actual discharge seconds of a 3300 at 30 amps.

By changing the calculation point of the average voltage it makes for a higher average voltage on the label. A cell will also lose more avergae voltage at the tail end of the discharge curve so by stopping the average before it gets to the end it makes even more of difference.
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