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Old Sep 21, 2012, 12:00 AM
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Mark, I don't understand why you are mad? I kept our conversation completely private even though I made it clear as to what i thought about vendor/mfgs who claim inflated C ratings.

You made your graphs public and were kind enough to share it with everyone, I simply responded with analysis to the data in those graphs. I was not the one who came on here to promote the sale of lipos which you claimed are 65C. Yes you told me you don't believe they are 65C either so why advertise them as such? The whole point of this thread is to help people and prevent them from being miss-lead by C ratings and in my opinion false Marketing.

I don't know you and I have nothing against you. I'm just simply pointing out facts from the data you provided. I'm sorry if you can't handle the that, but i wouldn't treat any other vendor trying to sell over rated batteries any differently.

I gladly told you I would test the 1800mAh lipos and post the results on here and my offer still stands if you want to take it.

Cheers
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Old Sep 21, 2012, 03:24 AM
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Melbourne, Australia
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Gents, could you take your discussion about personal issues off line or to a new thread please?

This thread was to discuss the use of IR as a measure of battery performance. We have had a fairly wide ranging discussion with plenty of heat at times but on the whole it has been pretty objective. This present development seems to me to in danger of becoming yet another typical forum slanging match.

Thanks.

John
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Old Sep 21, 2012, 11:38 AM
Battery Puffer
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I thought this thread was for posting resistance numbers of lipo batteries. I simply posted a graph of such and in no way was I trying to prove there 65c packs. For those of you that don't know C ratings from manufactors are derived from a formula that nobody understands except the manufactors. The only way to tell the performance of a battery is by resistance numbers. I poted mine. I don't make the C ratings on my packs nor do I agree with the c ratings of most manufactors. Sorry to take away anything from this thread. It was not my intention. I only wanted to see Dinogy packs added to the list.
Thanks for all the hard work you guys have done to make a list like this.

Mark
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Old Sep 21, 2012, 12:31 PM
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I've got to agree with MarkF here and to be honest thought it a refreshing change to see at least a lipo vendor if not a lipo manufacturer taking an interest and trying to participate in the system that Wayne Giles, Mark Forsyth and jj604 have championed. I thought the offer to provide Mark Forsyth with packs for annalasis was fantastic and now we see he extended that offer to jetspeedz too. I can see the difficulty for a vendor in MarkF's position as he states it's not him that labels the packs as 65C however I think the confusion comes from his first post in the thread here and particularly the highlighted statement

Quote:
Originally Posted by MarkF View Post
Jetspeed, please check out my website at performancerclipos.com
I sell what I think are the best packs around. I sell only 65C packs and so far only to top boating and airplane racers for the most part. Mark Forsyth I would like to get you a pack to try and test if you would like. I sold some 5s 1800 packs to an F5B pilot over seas and he say these are the best packs he has ever tested. He is pulling 180 amps on full throttle. My packs have a 6 month warranty as well. Let me know if your interested and I will get you the size you want. My website will change soon and be much better to navigate. Thanks for looking.

Mark
Going by the numbers posted for the 6S 5000mAh packs the F5B pilot pulling 100C from his 5S 1800mAh packs might find his packs not lasting too long unless he's running four of them in parallel. I'm not saying that to have a go at MarkF either but without actual numbers for the 1800's we can only go on what we have seen of other packs from the same manufacturer. I think we need to embrace MarkF's efforts and see if we can come up with a way to populate the database thread with the data of the packs he sells. It would be valuable information for us the consumer and may even help Mark with his business.
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Old Sep 21, 2012, 12:38 PM
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In other news, I missed the post today when my first Loong Max lipo's turned up but hopefully I can make it down to the post office in the morning. The first thing I will be doing with them is attempt to soak them at 22 deg C for a few hours before putting them on the Waynometer. If they pass that test I will be fitting them with my preferred connector and running a couple of break in cycles through them and testing them in between with the Waynometer. I will post results when I have them.
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Old Sep 21, 2012, 12:52 PM
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Quote:
Originally Posted by Aviefly View Post
I thought the offer to provide Mark Forsyth with packs for annalasis was fantastic and now we see he extended that offer to jetspeedz too. I can see the difficulty for a vendor in MarkF's position as he states it's not him that labels the packs as 65C however I think the confusion comes from his first post in the thread here and particularly the highlighted statement
To be clear i was not offered anything for testing by Mark, I requested a pair of packs to test and post the results but was denied!

Moving on, b/c of the data in the database I purchased a pair of Gens Ace 3S 1800mAh lipos which showed the most promise, so I will be testing and adding the results here and the 1/16 forums to see how it stacks up to the data. These packs are fresh and just came in so this is the newest batch from overseas.
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Old Sep 24, 2012, 03:04 PM
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Here is some values for two thunder power 1300mAh 3S 65C lipo

TP 3s 65c: one was 6, 11, 4 the other 8, 12, 8

This was given to me by another member which i requested the info.

Sadly the values are not as consistent as I thought they would be given TP's reputation of having consistent packs.

I'll be posting the Gens Ace values as soon as i get them
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Old Sep 26, 2012, 11:42 PM
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Hi all,

Compiled a few more results tonight and then sorted on FOM. Also included a PDF file of the FOM sorted data.

New files appended to post #1 of the Database thread: http://www.rcgroups.com/forums/showp...69&postcount=1

Enjoy.

Mark
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Old Sep 27, 2012, 02:33 AM
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Quote:
Originally Posted by mrforsyth View Post
Hi all,

Compiled a few more results tonight and then sorted on FOM. Also included a PDF file of the FOM sorted data.

New files appended to post #1 of the Database thread: http://www.rcgroups.com/forums/showp...69&postcount=1

Enjoy.

Mark
Mark,

Thanks for all that extra work; I hope it is appreciated and well used.
It certainly is simple to use as a reference and although there are sure to be some oddities and minor errors, the overall picture puts various packs where they should be in order of merit.

Wayne
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Old Sep 29, 2012, 06:08 PM
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Received a new Dinogy 3S 2250mAh 65C pack this week. Performed 4 mild break in cycles and then performed testing. Measured performance here. So far, this is the best performing lipoly that I personally have ever tested. I would put Dinogy on my short list if I were shopping for lipolys right now.

Mark
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Old Sep 29, 2012, 06:28 PM
Battery Puffer
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Thanks for doing the test Mark. I appreciate your efforts and the time it takes to do the testing.

Mark
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Old Sep 29, 2012, 06:44 PM
That's a funny word
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Thanks for the work Mark. Lots of data there.

I have RX a few testers from HK a few days ago and as per the reviews and comments on the HK site neither piece of equipment will be reliable for getting IR readings for the data thread. They may be ok for comparisons between packs for one user though. It is probably due to sharing the current and the measurement by only the balance lead. In otherwords they are testing the whole circuit resistance I think.

http://www.hobbyking.com/hobbyking/s...dProduct=22631 This read at least 4-5 times as much as my i-charger

http://www.hobbyking.com/hobbyking/s...dProduct=22412 This read about 10 times as much as the i-charger

Pretty consistent with the comments on the HK site.
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Old Sep 29, 2012, 07:04 PM
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Quote:
Originally Posted by mrforsyth View Post
Received a new Dinogy 3S 2250mAh 65C pack this week. Performed 4 mild break in cycles and then performed testing. Measured performance here. So far, this is the best performing lipoly that I personally have ever tested. I would put Dinogy on my short list if I were shopping for lipolys right now.

Mark
Hopefully, smaller sizes will become available in the near future?
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Old Sep 29, 2012, 08:31 PM
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Gulio,

Yes, I have lamented this fact more than a few times in various threads.

Accurate and reliable internal resistance testing can only be accomplished via 4-wire kelvin measurement with separate voltage sense and load carrying wires. If the same wires are used for both load and voltage sense, the net result is garbage due to the voltage drop in the load wires and connector. This drop can be negated somewhat if the wires and connectors are very substantial. Unfortunately, balance taps and wires do not qualify as being 'substantial' so all of these such devices are useless for measuring internal resistance of high performance lipolys.

I've personally found extremely accurate results with my iChargers and my Wayne Giles ESR Meter, both of which utilize true 4-wire kelvin technique.

Cheers,
Mark
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Old Oct 06, 2012, 12:55 PM
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Kemptville, Ontario, Canada
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Explain initial energy dissipation

Over on the Lipoly dbase thread mrforsyth tells us:
Quote:
Originally Posted by mrforsyth View Post
The results from the calculator are based on an initial energy dissipation of 6W/Ah which has been found to give acceptable performance without significant degradation for a wide range of lithium polymer chemistry batteries. This figure has been empirically determined and validated by three technically qualified modelers in three countries. http://www.rcgroups.com/forums/showthread.php?t=1577989.
I've done a seach for "initial energy dissipation" and the quoted post is the only place this is mentioned. I'd like to know more about this "initial energy dissipation". Can I get an explanation please?
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