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Old Oct 18, 2012, 01:07 PM
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United Kingdom, Aviemore
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Quote:
Originally Posted by ggcrandall1 View Post
Member Name ggcrandall1
Lipoly Mfr & Model Gens Ace 4S 4300 30C
Capacity 5300
C rating 30
Age (months) 1
Cycles 1
Cell IR 1.8
Temp 72.5
Equipment PL6
FOM 1.9
Max Cont. A 129
True C 24
quoted from the database thread.

Do you have some numbers mixed up somehow? you list the battery as a 4300 but then say its a 5300.
Even then with a cell IR of 1.8 the 4300 would come out at FOM1.55 , MaxA120 and a true 28C
At 5300 it would be FOM1.26, MaxA133 and a true 25C.
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Old Oct 18, 2012, 01:37 PM
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USA, GA, Marietta
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Quote:
Originally Posted by Aviefly View Post
quoted from the database thread.

Do you have some numbers mixed up somehow? you list the battery as a 4300 but then say its a 5300.
Even then with a cell IR of 1.8 the 4300 would come out at FOM1.55 , MaxA120 and a true 28C
At 5300 it would be FOM1.26, MaxA133 and a true 25C.
Typo.

5300mah
1.9 mohm
FOM = 1.19
Max current = 129
True C = 21

Glen
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Old Oct 19, 2012, 12:14 AM
Uh Oh Jungo
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Australia, WA, Perth
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Just a quick question. How sensitive are IR measurements to temperature? I've noticed some of the measurements in the database are done at temps ranging from 70f to 75f. Is there a large distortion comparing the True C of a battery measured at 70f to another at 75f?
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Old Oct 19, 2012, 12:29 AM
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So. Cal.
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Lipoly performance is definitely temperature dependent. Any modelers who fly in the winter or cooler climates can certainly attest to this fact. It's for this reason that I specifically requested in post #2 of the data thread that measurements be taken within 2 degrees of 72F (or within 1 degree of 22C). Within this narrow range, internal resistance does not vary much but I still requested that the temperature be noted so that the posted data would be of most value to the reader.

Mark
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Old Oct 19, 2012, 05:41 PM
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nice diagrams in post 2 and 3.
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Old Oct 20, 2012, 05:20 PM
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When looking for "cell damage,degradation,increased IR" is it more likely that it will show up at higher temps or lower temps? How about high voltage or low voltage? I'm reading mine with i-charger so I read only 1mv increments.

I 'think" I know the answer should be at the lowest temp and voltage since the IR is going to read the highest under those conditions.
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Old Oct 20, 2012, 08:05 PM
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It's generally easiest to track performance over time by being as absolutely consistent as possible with respect to measurement temperature. Charge state does not matter much at all as long as the pack has had the opportunity to stabilize. I typically measure at storage voltage (3.8-3.9 volt/cell) as I do not like to leave my packs at full charge any longer than necessary.

Fortunately, my living room is typically with 1-2 degrees of 72 F so maintaining a consistent test temperature is easy for me.

If your packs are truly degrading, the 1mOhm resolution of your iCharger will be more than sufficient to tell you this, unless your packs are huge (>5000mAh).

Mark
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Old Oct 25, 2012, 08:03 AM
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Land O' Lakes, FL
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I have been spot checking my HAIYIN packs IR during charging. So far, NONE has exceeded 1.0! When compared with my hyperions and various Hobbyking packs, the HAIYINs are MUCH lower in internal resistance. Just one more reason I have totally switched to HAIYIN for all new pack purchases.
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Old Oct 25, 2012, 08:42 AM
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Where do you buy them?
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Old Oct 25, 2012, 11:27 AM
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Originally Posted by JohnathanSwift View Post
Where do you buy them?
www.haiyinstore.com

Be sure to select USA Warehouse if you are in the US or European Warehouse if you are in Europe. Other countries can use HONG KONG Warehouse.
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Old Oct 25, 2012, 04:49 PM
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Quote:
Originally Posted by sailr View Post
I have been spot checking my HAIYIN packs IR during charging. So far, NONE has exceeded 1.0! When compared with my hyperions and various Hobbyking packs, the HAIYINs are MUCH lower in internal resistance. Just one more reason I have totally switched to HAIYIN for all new pack purchases.
Sounds very committed.

Out of curiosity, what's the capacity of these cells with a <1mOhm IR?
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Old Oct 26, 2012, 08:03 AM
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4S 5000 30C and 40C packs, 4S 2650 packs, and 6S 5000 packs.


Quote:
Originally Posted by H2SO4 View Post
Sounds very committed.

Out of curiosity, what's the capacity of these cells with a <1mOhm IR?
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Old Oct 26, 2012, 08:14 AM
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Quote:
Originally Posted by sailr View Post
4S 5000 30C and 40C packs, 4S 2650 packs, and 6S 5000 packs.
Even the 2650mAh cells boast IR less than 1 milliohm?
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Old Oct 26, 2012, 08:26 AM
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Yes, the 2650's I have checked were below or right at 1.0 mOhm
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Old Oct 26, 2012, 09:04 AM
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Quote:
Originally Posted by sailr View Post
Yes, the 2650's I have checked were below or right at 1.0 mOhm
That would give them a FOM of 4.53, a max current rating of 126A, and a 48 'true' C. A record, I believe.

What are you using to measure IR?
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