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Old 11-19-2008, 07:00 PM   #76
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Originally Posted by Trips View Post
In the good old days, a matcher would have a climate controlled room with a bunch of turbomatchers in it, and when they'd get a shipment of cells they could process a whole bunch in a workable time frame.

Turbomatchers won't work with liPO's, they can't charge them and from what I remember of mine, there's no way to set a discharge cutoff voltage that would work with a LiPO cell.

That leaves a matcher in the unenviable position of running every LiPO cell on a Turbo35GFX to get similar numbers... it would take forever (or a crapload of Turbo35GFX's, not an attractive proposition) to process a batch of LiPO cells, because a Turbo35 GFX can handle one cell at a time, where a turbomatcher could handle 4, 6 or eight at a time depending on which models you had.
Cells are matched by our supplier and then assembled into packs. When then take these packs and cycle them as a pack on the GFX. There is no need to cycle single cells.
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Old 11-19-2008, 07:00 PM   #77
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Have not miss the point , and still say when SMC introduces its 35C they will howl same as now when the other`s come out with 40C.....

If SMC says C-ratings are not truth full, why even
use C ratings on their products ?
SMC uses a C rating because that is how you test lipos. There C ratings are excellent and accurate. I had a 35c pack that was not even close to performance as an SMC pack-
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Old 11-19-2008, 07:04 PM   #78
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I may be able to answer this one-
people will buy the biggest, think about it, if one says 25, and the other says 30, bigger is better right?

its all marketing, true numbers or not.

Remember the old panasonic 3600's? they sucked!! yet, people still purchased them because they where "bigger" than 33's, regardless of actual cell facts.
This is just part of the nature of the racer that they always want the best , biggest and greatest. This is why were seeing many false claims when it comes to Lipos.

With sub-c cells it has happened more than once that a cell with higher capacity wasn't better and inf fact was worse than one with lower capacity but many racers bought the latest and greatest only to find out it wasn't.
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Old 11-19-2008, 07:05 PM   #79
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It doesn't really make sense for ROAR to worry about C rating or mAH hour as a manufacturer can submit packs with true C rate and mAH and then sell packs with lower C rate cells. Unless ROAR wants to start buying packs from every company from time to time to check as see what they are selling but that could get pricey.

Potentially, ROAR could go to a LHS six months after the fact and purchase product under suspicion though. Pricey or not - this is what the membership depends on... the products on the list are truly evaluated as per the rules and the ROAR Approval stamp is on it.

As of 1/1/09 - lipos will have to carry the ROAR approved label over the seam so we can detect tampering as well.

Danny - your thread here is a FANTASTIC thing and EXACTLY what you have said must be out there. I thank you for this and I'm greatful you are going to be first in line with the new ROAR approval system.

Its all about moving with the times and changing as the technology changes.
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Old 11-19-2008, 07:08 PM   #80
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Originally Posted by Wild Cherry View Post
Have not miss the point , and still say when SMC introduces its 35C they will howl same as now when the other`s come out with 40C.....

If SMC says C-ratings are not truth full, why even
use C ratings on their products ?
You missed the point.

C rating is the proper way to rate Lipo, but he is just pointing out that some other brands are fudging the numbers.

This is the same crap with LCD monitors and response time, no standard for reporting, so while some companies give meaningful numbers, other will report false numbers using a BS standard to make their panels look faster.

But in both cases, if you know HOW they are obtaining the number then you can make educated choices.

All Danny has done is point out how SMC gets it C rating and that other fudge the numbers.


Look if none of you care that you're paying inflated prices for a pack with inflated numbers, don't attack Danny.
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Old 11-19-2008, 07:08 PM   #81
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Originally Posted by Dawn Sanchez View Post
Potentially, ROAR could go to a LHS six months after the fact and purchase product under suspicion though. Pricey or not - this is what the membership depends on... the products on the list are truly evaluated as per the rules and the ROAR Approval stamp is on it.

As of 1/1/09 - lipos will have to carry the ROAR approved label over the seam so we can detect tampering as well.

Its all about moving with the times and changing as the technology changes.

Dawn

So will this make previous approved pack non compliant??

Or will this new ruling not effect pre 2009 approvals

Thanks
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Old 11-19-2008, 07:10 PM   #82
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Dawn

So will this make previous approved pack non compliant??

Or will this new ruling not effect pre 2009 approvals

Thanks
Will not effect prior 2009 approvals. Although, we do encourage MFG's to start using the labels on new quantities of already approved product.
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Old 11-19-2008, 07:13 PM   #83
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Originally Posted by Dawn Sanchez View Post
Potentially, ROAR could go to a LHS six months after the fact and purchase product under suspicion though. Pricey or not - this is what the membership depends on... the products on the list are truly evaluated as per the rules and the ROAR Approval stamp is on it.

As of 1/1/09 - lipos will have to carry the ROAR approved label over the seam so we can detect tampering as well.

Danny - your thread here is a FANTASTIC thing and EXACTLY what you have said must be out there. I thank you for this and I'm greatful you are going to be first in line with the new ROAR approval system.

Its all about moving with the times and changing as the technology changes.
I think it's a great idea as we have nothing to hide and we don't play games. That is why our packs have odd C rates as we take pride in what we sell.

It will also save us money from having to buy test equipment to prove to everyone who is honest and who isn't.
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Old 11-19-2008, 07:16 PM   #84
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Will not effect prior 2009 approvals. Although, we do encourage MFG's to start using the labels on new quantities of already approved product.

Will the label printing be up to the manufactures , the OEM supplier Or will ROAR be suppling the Labels at a fixed cost??


I assume their will be a Label template if the latter is not the case
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Old 11-19-2008, 07:17 PM   #85
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danny

this may be off topic,

but how do i store my lipo packs full charge, low charge

how do i "cycle" them on my lipo gfx????(where do you hook the leads)
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Old 11-19-2008, 07:19 PM   #86
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I don't understand what your testing method would achieve ?

So I would take a pack and discharge it @ 135 amps for 60 seconds then what would that tell me ?

I will take it slow for everyone to catch up. There is a maximum power point to every battery. At some point the battery can not take any more load and the total wattage is decreased by the reduced votlage.

Using the SMC chart, I made my own speculation
Watts on the X, Load in AMPS on the Y

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Old 11-19-2008, 07:25 PM   #87
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Originally Posted by mr. losi View Post
danny

this may be off topic,

but how do i store my lipo packs full charge, low charge

how do i "cycle" them on my lipo gfx????(where do you hook the leads)
If you run them every week or couple of weeks I would store them discharged down to 6 volts at 35 amps with your GFX. I know a Lipo can stay discharged for a long period of time as they reltively don't selfdischarge that much. For long time storage I would put a bit of charge like charging it until the voltage reaches 7 volts. In some of my testing lately I see that storage charge tends to remove some capacity from the packs and in some cases I see the IR goes up a bit and the voltage drops. If your not racing in class where power is everything then you don't need to worry about this as the drop in performance is not huge.

I assume your using connectors on your packs ? If so look at the picture below this is how you can attach the voltage sensing leads. Typically a Deans connector will increase the IR by 1.5 milliohms and drop the voltage by .04 under a 35 amp load.
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False Lipo advertising-voltagelead-hookup.jpg  
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Old 11-19-2008, 07:28 PM   #88
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trailranger: I'm not great with ohms law but if I were to test different packs at 135 amps for 60 seconds what info would I get and how would that be different than discharging a pack at 135 amps down to 6 volts and giving the info ?
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Old 11-19-2008, 07:29 PM   #89
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Originally Posted by Johnny Carey View Post
SMC uses a C rating because that is how you test lipos. There C ratings are excellent and accurate.
Capacity was how they used to rate Sub C Nicads. The GE 1000 mah cells were good, way back in the day, then the Sanyo 1200's were better. Then Bob Emott started matching batteries for runtime. I don't know if he was the first to match cells, but was among the first for sure. For a while, then, RUNTIME was how you tested Nicads. Then along came average voltage and internal resistance, and THAT was how you tested Nicads (and NIMH's)

The reason LiPO's are rated by C rating isn't because it's the "right way", it's because LiPO technology in R/C racing is still in its infancy. When the technology catches up, we'll see LiPO's rated by average voltage and IR as much as C rating. My whole reason for making comments in this thread was to hopefully get folks to want to see that information. I applaud SMC for printing discharge information on their LiPO packs.

Quote:
I had a 35c pack that was not even close to performance as an SMC pack-
Once again, are you sure the difference in performance was due to the SMC pack having a better C rating than the alleged 35C pack? I'd bet a year's salary that if you charged each pack on a good LiPO charger, then put each on a Turbo35GFX and discharged them at 30 amps down to 7 volts, the SMC would show higher average voltage and lower IR than the alleged 35C pack...
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Old 11-19-2008, 07:36 PM   #90
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all I know is that my SMC pack out perform my "other" packs...from this point on its all SMC for me
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