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Old Dec 27, 2012, 12:36 AM
aka JetMan Joe
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Originally Posted by ivaylo goranov View Post
No the load is not the same. It can not be the same if the IR of the Cell are not equal. But if it is programed, could be the same.
The tests are with purpously designated devices Load tester with heat extraction and calculas

Hey Ivaylo, don't be highjacking my thread, that question was posted to me, not you. Thanks.
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Old Dec 27, 2012, 12:38 AM
aka JetMan Joe
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Originally Posted by LoneWolfRC View Post
Awesome thread, looking forward to the brushless or pulsed inductive load testing, just to learn what sort of differences there might be.

Did you use the same resistance for all of the tests, or did you pick different taps for each battery?
I ran all the tests on this list using the resistance value that would generate ~180A on 6S under ideal conditions. I've also ran tests using higher resistances (lower amps) but it seems that the lipos I've tested don't show much difference under 150A loads. That in itself told me that, other then total life cycles most any brand will serve well at the lower amp ranges. I got interested in testing when I started flying 10S and 12S jets running up to 180A and found the battery choice could count for over a 20mph top speed change.
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Old Dec 27, 2012, 01:55 AM
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Hey Ivaylo, don't be highjacking my thread, that question was posted to me, not you. Thanks.
Sorry I did not know to whom was addressed the question!
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Old Dec 27, 2012, 09:24 AM
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Originally Posted by MCSGUY View Post
I've also ran tests using higher resistances (lower amps) but it seems that the lipos I've tested don't show much difference under 150A loads. That in itself told me that, other then total life cycles most any brand will serve well at the lower amp ranges.
It SEEMS to me that different brands do give a difference in plain performance. I fly 3D and running 80 amps and below. I find that cheaper batteries sag more when given full throttle to punch out of hover for example.

But this "finding" is based purely on the "feel" of the plane as I fly. Is my mind just playing tricks on me?
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Old Dec 27, 2012, 10:25 AM
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Originally Posted by ivaylo goranov View Post
Sorry I did not know to whom was addressed the question!
No problem, I appreciate your contributions.
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Old Dec 27, 2012, 10:54 AM
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It SEEMS to me that different brands do give a difference in plain performance. I fly 3D and running 80 amps and below. I find that cheaper batteries sag more when given full throttle to punch out of hover for example.

But this "finding" is based purely on the "feel" of the plane as I fly. Is my mind just playing tricks on me?
I don't think so because I've noticed the same thing with my 3D planes. I think that is where we might notice the difference between resistive and inductive loading results. I'm almost ready to begin testing another set of batteries. I have to break some in first but I'm going to Eagletree a Schubi 127mm DS94 fan that will draw up to 180A on 12S and plot the comparisons for a 60 second WOT run. Probably be a week or two before I can post the info.

So far what I've seen that effects 3D "punch out" is the voltage level held under load. Seems like some batteries rated at similar C values will hold 3.9v per cell under load while another drops to 3.6v under the same load. I've done some IR testing using the Cell Pro "AC carrier" type method which is supposed to be more accurate (at least the mfg claims it is) and while I've seen similar IR's for TP and GensAce (in fact GensAce have shown lower IR values per cell) but they don't kick like the TP's do into the middle of the flight. There's a lot I don't understand.
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Old Dec 27, 2012, 05:57 PM
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I hear ya' Very interested to see next results!
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Old Dec 27, 2012, 06:09 PM
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Originally Posted by MCSGUY View Post
I ran all the tests on this list using the resistance value that would generate ~180A on 6S under ideal conditions. I've also ran tests using higher resistances (lower amps) but it seems that the lipos I've tested don't show much difference under 150A loads. That in itself told me that, other then total life cycles most any brand will serve well at the lower amp ranges. I got interested in testing when I started flying 10S and 12S jets running up to 180A and found the battery choice could count for over a 20mph top speed change.
It would be nice to know what the resistance was for each battery tested.
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Old Dec 27, 2012, 06:43 PM
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If my memory serves it was 0.125 ohms, I'll dig up my receipt and confirm. I was figuring a loaded cell voltage of 3.75 x 6 cells = 22.5v, so E=IR; 22.5=180A x 0.125
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Old Dec 28, 2012, 12:45 PM
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Oh, so you did use the same resistance for all of the 6S batteries...that is good to know. Makes the revolecrix you tested look that much better.

Speaking of which, did you get sample batteries provided, or did you buy all of the batteries without telling the vendors that you were going to use them for testing, or some other combination?
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Old Dec 29, 2012, 02:50 AM
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Bought everything outright, didn't mention it to suppliers until after. Since then I have been asked to include another brand in the up coming inductive testing. The supplier contacted me and wanted to send packs out so I will make a note to that effect in the results.
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Old Dec 29, 2012, 02:54 AM
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Bought everything outright, didn't mention it to suppliers until after. Since then I have been asked to include another brand in the up coming inductive testing. The supplier contacted me and wanted to send packs out so I will make a note to that effect in the results.
Good news. Man, I have to thank you for all the time and trouble. It is really appreciated, and should be by all.

If you know anybody with the same battery they're sending, it would be really good to double check to make sure they're not cherry picking.
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Old Dec 29, 2012, 09:58 AM
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Originally Posted by LoneWolfRC View Post
If you know anybody with the same battery they're sending, it would be really good to double check to make sure they're not cherry picking.
Yeah, What brand is it?
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Old Dec 29, 2012, 12:00 PM
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"Dinogy", the supplier (MarkF) says he will probably send in the set he ran at Namba Nationals so they won't be as fresh as some I'll be testing but they'll be good and broke in. Looks like they're priced to match Revolectrix (or visa versa )
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Old Dec 31, 2012, 02:23 AM
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I don't think so because I've noticed the same thing with my 3D planes. I think that is where we might notice the difference between resistive and inductive loading results. I'm almost ready to begin testing another set of batteries. I have to break some in first but I'm going to Eagletree a Schubi 127mm DS94 fan that will draw up to 180A on 12S and plot the comparisons for a 60 second WOT run. Probably be a week or two before I can post the info.

So far what I've seen that effects 3D "punch out" is the voltage level held under load. Seems like some batteries rated at similar C values will hold 3.9v per cell under load while another drops to 3.6v under the same load. I've done some IR testing using the Cell Pro "AC carrier" type method which is supposed to be more accurate (at least the mfg claims it is) and while I've seen similar IR's for TP and GensAce (in fact GensAce have shown lower IR values per cell) but they don't kick like the TP's do into the middle of the flight. There's a lot I don't understand.
Yes
It is sensitive diference of the battery performance due to inductivity.
Also the inductivity increases with the working cycles numbers more then Ohmatic component of the Resistanse (impedance)

One more point of matter should be considered: it is the proportion between free ions and capacity formatted on the electrodes.
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