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Old Mar 14, 2011, 01:57 PM
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TEST: Turnigy Nanotechs v Turnigy Std. v LM Tipples

I recently bought two Turnigy Nanotech 3S2200 25C packs for my own use in a WOT 4 Foamie and was surprised at how high the ESR cell values were on the 25C packs. So much so that I posted the readings at:-
http://www.rcgroups.com/forums/showthread.php?t=1384403

I also bought a 3S2200 45C Nanotech at the same time which looked a lot better.

I have now done some power discharge runs on both packs and carried out identical runs on a Loong Max Tipple 3S2300.25C pack, a LM Tipple 3S2300 40C pack and a standard Turnigy 3S2200 25C pack as comparisons.

As I said in the original post, I did not think that the 25C Nanotech was capable of a full rated discharge and so it turned out. As it was incapable of a 25Cdischarge, comparative figures are taken at 20C and it showed excessive temperature rise and some puffing at that discharge rate.

My conclusions, based on voltage drop and final temperatures, are:-

(a) The Turnigy Nanotech 25C pack is only really a 15 Ė 18C pack, really struggling at 20C, way outstripped by the Tipple 25C.
(b) The Nanotech is also well outstripped by the standard 25C Turnigy (almost 2 year old pack I have which has had severe treatment)
(c) The Turnigy Nanotech 45C is much better, only just beaten by the Tipple 40C, but both of these should realistically be rated at 30C.

It may be that the two new 25C Nanotechs I purchased (both the same) are from a poor batch; if so itís a QC problem, if not then the claims for them are quite unjustified. Iím not inclined to buy more to prove the point either way.
It may be that the old standard Turnigy 25C was an exceptionally good example but that just makes it a lottery; we may as well buy this much cheaper one.
Equally, it may be that the cells presently used in the standard Turnigy packs are not from the same maker as 2 years ago.

Wayne
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Old Mar 14, 2011, 02:10 PM
BrainFart RC-Pilot
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Wayne,

Thanks for the info!
I will try this season the Nano 2200 25C compared to the Rhino 30C 2150.
The Nano 25C are 177gram (with 3.5mm lead plugs), so very light. Lighter then the Rhino which are 184gram.

Are there big differences in weight?
Nano25C compared to regular 25C Turnigy?

I know that the 45C of Nano are more heavy.
They have more volume, which leads to higher C ratings.
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Old Mar 14, 2011, 02:38 PM
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Hi Wayne,
Thanks for posting those results. I have Turnigy 2200 mAh 3 S 25C these have been bought over an 18 month period and they have all given good service.

I reckon I will steer clear of the nanotech packs.
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Old Mar 14, 2011, 03:38 PM
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Straight and to the point. I like that Wayne. Thanks!!!

Rick
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Old Mar 14, 2011, 03:45 PM
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Thank you. It's nice to get data with a bit more substance than "This battery is great".
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Old Mar 14, 2011, 04:59 PM
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Great work Wayne!
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Old Mar 14, 2011, 08:56 PM
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Thanks Wayne for the valued info.

I have same experience with my two year old heavily used Turnigy 6s5000mAh. It's been far beyond my expectations.

Would be great if you make a similar comparason between the standard Turnigy and the Hyperion G3, IR, capacity and life span. I did and had very interesting results.
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Old Mar 14, 2011, 10:15 PM
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Is it just me or are those some disturbingly flat discharge curves? Just wondering what type of load / controller you're using Wayne? I've studied mountains of lipoly discharge curves over the past 5 years and these are very atypical for current generation cells (at least in my estimation). Perhaps it's because nearly all others were from WMR CBA controller and it's perhaps inherently inaccurate? Or maybe it's because your Y-axis goes to zero and typical CBA curves truncate below cutoff voltage? Perhaps I need a nap???

Have you ever run your test setup with a current shunt in series and a DVM in parallel to validate accuracy? I think I am going to do that now with my CBA as your crazy flat graphs have me perplexed....

Nice work, btw (as usual).

Mark
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Old Mar 14, 2011, 10:41 PM
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Quote:
Originally Posted by mrforsyth View Post
Or maybe it's because your Y-axis goes to zero and typical CBA curves truncate below cutoff voltage?
I'd say that's the reason. I find in my Eagle Tree graphs, if the Y-axis goes down to zero, the discharges appear extremely flat. On the other hand, if the range is between 9 and 13 volts they look dramatically different.
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Old Mar 14, 2011, 10:44 PM
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Without taking a closer analysis I'm certainly inclined to agree with you Eric. Will make a more concerted effort over the next few days when I'm more lucid. Work got too much from my brain today...

.1V/cell drop over the middle 50-60% of the discharge is just a bit difficult for me to comprehend. Not saying it's not possible, I've just never seen it.

Mark
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Old Mar 15, 2011, 07:05 AM
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Thanks for all the kind words everybody.

TDr,
Weights with XT60 on each pack are:
Turnigy Nan 25 :176g
Turnigy Nan 45 :204g
Turnigy Std 25 :188g
Tipple 25 :190g
Tipple 40 :204g

I agree that the better packs are slightly heavier, but it is something of a red herring as the difference between the Tipple and Turnigy 25C packs is 14g which is just about 1% of the model weight (1.4Kg), whereas the likely difference in power level at 50% discharge is about 7%.

Sparklet,
If you have the latest Turnigy std pack, is it as good as the older ones?

Himalaya,
Don't keep us in suspense! were they good or bad?

Mark,
Two reasons for the flat curves; one is, as you and Eric surmise, because it is a complete plot, ie it does not have a suppressed zero, which I think would distort the results. (More accurately I don't have a clue how to display it with the Medusa software!)
The other reason is because most of the plots are showing the performance at or near the limit of the cell's capability so that the heating and consequent reduction in IR is compensating for the falling voltage due to level of discharge.
Flightpower claimed that this was done deliberately on their EON-X lipos to give flat discharge, but it sounds like an excuse for high IR figures to me.

One of my 'Rules of thumb' (not necessarily correct) is that if a pack actually sags in voltage and recovers during a discharge, then it is overstressed; the recovery is due to excessive self heating. If you look at the first table, you will see that the 25C Nanotech at 20C shows a lower voltage at 15 secs than at 50% discharge which is a case in point.
BTW the table voltages are taken via the balance connector and represent total cell voltage. The plot comes from the Medusa which must include some connector + lead drops.
The discharger is a homebuilt CC unit (see photo) but it is accurately calibrated, agrees with the Medusa and drifts < 0.3% at 66A load. This is due to the small +ve temp.coefficient of the ceramic power resistors.

Now I need a nap!

Wayne
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Old Mar 15, 2011, 08:17 AM
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Quote:
Originally Posted by Wayne Giles View Post
Thanks for all the kind words everybody.

TDr,
Weights with XT60 on each pack are:
Turnigy Nan 25 :176g
Turnigy Nan 45 :204g
Turnigy Std 25 :188g
Tipple 25 :190g
Tipple 40 :204g

I agree that the better packs are slightly heavier, but it is something of a red herring as the difference between the Tipple and Turnigy 25C packs is 14g which is just about 1% of the model weight (1.4Kg), whereas the likely difference in power level at 50% discharge is about 7%.

Wayne
Yes...good one. The weight of a pack is in some cases essential.
Therefore I picked the Nano25 instead of the Nano45....also because I use only 10C static with this plane. (SU-26m of 1kg)

Still, only a few gram indeed...and they are compensate with more punch and power.

I most case using higer C rating (more weight) makes sense, since it are only a few gram. That is fully clear to me!
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Old Mar 15, 2011, 09:51 AM
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The fan blades look awesome, must be very cool when spin up. Were they bought that way or you painted them red?

As of Hyperion vs Turnigy, I feel a bit nervous to post the result as it shows the old saying "you got what you paid for" might not always work so accurately.
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Old Mar 15, 2011, 03:32 PM
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Hi Wayne,
The latest Turnigy packs I have were probably bought late last year. I have seen no difference between them and others I bought around 14 months or so earlier.
My packs have been bought over the 18 month period - maybe longer my memory is not as good as it used to be.

I use two 2200 mAh packs in parallel and they deliver 38 amps for my, reasonably large, aerial photography planes.
They are usually required to provide 38 amps for between 1 and 2 minutes to pull models weighing around 4.4 lbs up to nearly the limits of my vision, they then glide until asked to power up again. I reckon on 5 climbs to stay on the safe side.
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Old Mar 15, 2011, 06:10 PM
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Thanks a lot for the thoughtful response Wayne.

I understand that your table and graph source data is measured at different locations (cell vs. Medusa controller). I surmise that this accounts for the difference in programmed cutoff (9.0V) vs. plotted cutoff (~8.6-8.9V) in your graphs (that is due to lead and connector IR drop)?

Do you happen to have the graph source data? Might be interesting to recompile and then fiddle with the axes...

Charles tested the 45C 2200 Nano's back here and his curves were not near as flat, even taking into account suppression below cutoff. Granted, he only tested to 50 amps and I'm willing to concede that negative temperature coefficient effects will be more pronounced and produce a flatter curve at your listed 66A dump. Might be interesting to repeat at a lower draw to corroborate his Nano sample.

Thinking out loud - I'm wondering if it would be possible to calculate cell temperature coefficient if one knows starting voltage, ending voltage, recovered voltage, beginning cell temp, and terminal cell temp....

Mark
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