False Lipo advertising
11-19-2008, 04:08 PM
#46
not all manufactors use the same test to get a "c" rating, so until that is done, its pretty much useless info when comparing lipos, that is unless someone is willing to take a sample of all the labels and run them through tests, and these 'test' batteries need to be random off the shelf batteries and not factory or label test batteries. IMO
11-19-2008, 04:09 PM
#47
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.
Perhaps ROAR should do this occasionally , Seeing they are the Governing and ruling Body , It would only have to be at random and structured into the approval costs.
As menttioned i do beleive the "C" rating issue is more important that seeing if a hard case meets a drop test??
11-19-2008, 04:14 PM
#48
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Correct me if I'm wrong:
3T 540-size sensored brushless is less than 900W. LRP says its X12 3T is 797W but at what voltage? So lets say it is maximum 900W which at 7.4V makes 121A. When we consider ESC's internal resistance we can say that the MAXIMUM current can go up to 125A.
For 5Ah battery it has to be 25C to give out the 125A. So we don't need more than 25C capable 5Ah battery. Newer hardcase LiPos go up to 5300-5400mAh capacity. To get 125Amps from 5400mAh LiPo it has to be only rated at 23C.
3T 540-size sensored brushless is less than 900W. LRP says its X12 3T is 797W but at what voltage? So lets say it is maximum 900W which at 7.4V makes 121A. When we consider ESC's internal resistance we can say that the MAXIMUM current can go up to 125A.
For 5Ah battery it has to be 25C to give out the 125A. So we don't need more than 25C capable 5Ah battery. Newer hardcase LiPos go up to 5300-5400mAh capacity. To get 125Amps from 5400mAh LiPo it has to be only rated at 23C.
11-19-2008, 04:15 PM
#49
not all manufactors use the same test to get a "c" rating, so until that is done, its pretty much useless info when comparing lipos, that is unless someone is willing to take a sample of all the labels and run them through tests, and these 'test' batteries need to be random off the shelf batteries and not factory or label test batteries. IMO
Normally the industry standard is 90% but some do go down to 80%. If you read my first post some are way off and I have no issue with those who use 80% and say so. The problem is when you claim 35C and it's only 80% at 25C that is a big difference.
Last edited by Danny/SMC; 11-19-2008 at 04:45 PM.
11-19-2008, 04:25 PM
#50
not all manufactors use the same test to get a "c" rating, so until that is done, its pretty much useless info when comparing lipos, that is unless someone is willing to take a sample of all the labels and run them through tests, and these 'test' batteries need to be random off the shelf batteries and not factory or label test batteries. IMO
Yet, SMC uses the same standard & prints C-rating on its Li-Po products .....
11-19-2008, 04:38 PM
#51
I'm actully thinking of doing such a test. If I do it I will be accused of bias so I my purchase the equipment and packs and let an independent person so the test.
Normally the industry standard is 90% but some do go down to 80%. If you read my first post some are way off and I have no issue with those who use 80% and say so. The problem is when you claim 35C and it's only 80% at 25C that is a big difference.
Normally the industry standard is 90% but some do go down to 80%. If you read my first post some are way off and I have no issue with those who use 80% and say so. The problem is when you claim 35C and it's only 80% at 25C that is a big difference.
11-19-2008, 04:42 PM
#52
I still see a simple solution
MAX WATTAGE @ LOAD CURRENT
Example 1000W @ 135A
60 second test....average the sustained wattage.
Like I said, this test would not be a subjective test. It would be repeatable and easy to compare other batteries.
The C rating has no standardized test to compare C rating. Some use C as a safety barrier, others as a 90% capactiy limit.
MAX WATTAGE @ LOAD CURRENT
Example 1000W @ 135A
60 second test....average the sustained wattage.
Like I said, this test would not be a subjective test. It would be repeatable and easy to compare other batteries.
The C rating has no standardized test to compare C rating. Some use C as a safety barrier, others as a 90% capactiy limit.
11-19-2008, 04:43 PM
#53
11-19-2008, 04:48 PM
#54
I still see a simple solution
MAX WATTAGE @ LOAD CURRENT
Example 1000W @ 135A
60 second test....average the sustained wattage.
Like I said, this test would not be a subjective test. It would be repeatable and easy to compare other batteries.
The C rating has no standardized test to compare C rating. Some use C as a safety barrier, others as a 90% capactiy limit.
MAX WATTAGE @ LOAD CURRENT
Example 1000W @ 135A
60 second test....average the sustained wattage.
Like I said, this test would not be a subjective test. It would be repeatable and easy to compare other batteries.
The C rating has no standardized test to compare C rating. Some use C as a safety barrier, others as a 90% capactiy limit.
So I would take a pack and discharge it @ 135 amps for 60 seconds then what would that tell me ?
11-19-2008, 04:54 PM
#56
11-19-2008, 04:56 PM
#57
See there Danny , you use C-rating , yet condeem others for doing the same ...
Thats the bad...
BDW do I need a hotplate to heat your product before testing ?
I have no doubts SMC will be manufacturing 35c real soon ....
Then do the same like now when the other company`s comes out with a 40c....
Thats the bad...
BDW do I need a hotplate to heat your product before testing ?
I have no doubts SMC will be manufacturing 35c real soon ....
Then do the same like now when the other company`s comes out with a 40c....
11-19-2008, 05:01 PM
#58
See there Danny , you use C-rating , yet condeem others for doing the same ...
Thats the bad...
BDW do I need a hotplate to heat your product before testing ?
I have no doubts SMC will be manufacturing 35c real soon ....
Then do the same like now when the other company`s comes out with a 40c....
Thats the bad...
BDW do I need a hotplate to heat your product before testing ?
I have no doubts SMC will be manufacturing 35c real soon ....
Then do the same like now when the other company`s comes out with a 40c....
Yes we use C rate as this is how Lipos are rated so what are you trying to say ?
No we have no plans on manufacturing a 35C pack.
11-19-2008, 05:02 PM
#59
ok i was wonderin how liposuction was false advertising since ur taking away not adding. now it makes sense....
R
R
11-19-2008, 05:13 PM
#60
Everything I've ever known leads me to look at voltage, IR and runtime to determine how my packs will perform on the track. You discolsed those numbers on every NIMH cell I ever bought from you. All I'm saying is I'd like to see everyone selling LiPO's disclose those same numbers so I can make an informed choice.
I understand it's not like you can put eight LiPO cells into a turbomatcher (I[m not even sure if a Turbomatcher has the settings range to do this, after all you can't take a LiPO down to .9 volts, and I KNOW the Turbomatcher can't safely charge a LiPO cell, so there is definitely a logistical problem facing you if you want to do this...
I also know that higher C ratings usually indicate lower IR, but I'd just like to see a move toward publishing the numbers that actually matter to me...
Would it make sense to choose my real car's tires based on whether they are H rated (SAFE TO 130MPH) or V rated (safe to 149 mph) when I'm driving a car that will never see the better side of 80mph? Or would it make more sense to look at skidpad numbers to comparison shop (if I'm looking for the highest grip) or mileage numbers (if I'm looking for longest life)??? Suppose I bought H rated tires that tested to be grippier than some other set of V rated tires? Would I worry that i was paying for something I wasn't getting No, because again, it's something I don't need.
