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LiIon, LiPo, NiCd & NiMh General General Battery Support


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Old 05-06-2012, 03:44 AM   #1
Heli,Ed
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Default How much IR is too much

I will get the exact readings later today,but I got 2 different 6s packs out of all of the that have an ir of about 1.5 on 5 cells and then as high as 18 to 20 on the other cells
one is a year old turnigy 5000 mah with tons of flight on it,the other is a 30c 5300 mah gens ace with only about 17 cycles on it
(I thought gens ace was suppose to be good batteries)
I have heard that high ir means a cell is about to fail,and if it does the whole heli will loose power and crash
If there is already a discussion on HF let me know so I do not take up need server space
Thanks in advance

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Old 05-06-2012, 11:16 AM   #2
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Assuming the measurement method is valid and accurate a difference of about 20% across all cells can indicate the cell is aging faster than the others. The difference you are describing is on the extreme side and I would validate the measurement method before drawing conclusions. If in fact the values are correct, you would most likely feel heavy bogging under load while flying. Two questions for you:
  1. How are is the IR being measured? What device and at what ambient temp? Standard practice is to let the pack rest at 70f for at least an hour before measuring.
  2. In the pack which cell is showing as high? If its cell #1 or cell #6, is this the cell the rests against the model, or is on the outside of the pack?
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Old 05-06-2012, 11:30 AM   #3
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Is it the same cell on both packs that's showing a high value?

Also, what's the state of charge when taking the IR reading? I find that fully charged packs show much lower numbers than discharged ones.
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Old 05-06-2012, 01:39 PM   #4
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I am using a Power Lab 8.The batteries were taken from perfect storage mode and for first charge of the day at 6:30 am with temps around probably 70 degrees or slightly higher ,and taken from an air conditioned car
I never had a charger before that would read ir so this is great to see the condition of the batteries now
I actually found and recorded the highest and lowest ir for several packs but did not think to see what position the readings were in but if memory serves me they were 1 and 6 on all the packs
I will make sure to take note next time exactly what position the low and highest readings were in
Also the ir was about the same,if not slightly lower on the high reading after flying and re-charging a next time
The lowest to highest ir was as follows if it helps
Turnigy 40-50c 5000 mah
#1 was 1.1 and 11.4
#2 pack was 1.3 - 8.6
Gens Ace 5300 mah 30c with 28 cycles was 1.2-13.9
Pack #2 with 29 cycles was 1.2- 13.9
I have 1 voltz pack I did not get a chance to get the ir on
All of the batteries end up balancing perfect straight across to 4.20 per cell when full charged
All of them are always put into storage mode when done,and I never max out the charge rate
The gens ace and the turnigy batts are rated to take a 5c charge but I never exceed 3c in the beginning of the day to get going on the first 2 packs and then charge everything at 2c for the rest of the day
Strange thing
The Gens Ace are nearly new and well cared for and have worse readings than the cheaper hobby king turnigies
The turnigy batteries have a huge amount of cycles on them from flying a 600esp for the whole last summer
I now am flying 550s and they are under less stress from power to weight ratio being better
I will receive 2 brand new Turnigy nano-techs 45-90c 5000 mah packs Wednesday and am anxious to see how they do
If it were not for having a charger good enough to tell me ir I would not even be able to know this ir info
And would be like most people that just charge and fly them until they do not have any power left anymore
Does a high ir mean that a cell is in fact going out and what is the highest ir acceptable to still use a pack
BTW Thank you all Soooo much for taking the time to help me muddle my way through yet another learning curve and process
Next I will be looking at finding out which battery if=s the best bang for the buck
Thunder Power is way so expensive but are they worth it
If my cheapo hobby king batteries are so much better off so far than the gens ace,(maybe gens ace are not so good as I thought ?)
Sorry for the overload of info,but maybe it will help
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Old 05-06-2012, 01:41 PM   #5
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One more thing
The ir reading is while the charging process.I did find a way to check ir after they are charged but did not have time to do it today,but now that I know how to do it that will be my next step in getting a more accurate measurement
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Old 05-06-2012, 03:42 PM   #6
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Thanks for the details. A couple things that will help improve your readings. The IR reading on the Powerlab8 is sensitive to differences in resistance on the two charge cables. For example a user installed a fuse on the red (+) wire but not the black wire. Electrically this should not be an issue. That was enough to cause invalid readings one cell.

I have found that even dirty contacts on my connectors between charge cable and the battery will cause reading issues. A quick cleaning with alcohol corrected my issues. The reading errors will either be on the first or last cell.

Finally,if you are using JST-XH wiring mode, then you need to upgrade to the latest firmware. There is an enhancement to improve the IR reading, but only for the JST-XH wiring mode.
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Old 05-06-2012, 07:08 PM   #7
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Gregor99
I bought it about 4 months ago and did update it then.I am using jst and thus will make sure that is has the latest update for sure
The parallel board is new and so is the balance leads.I am using the revelectric 6 output fused board,(Maybe the board could cause mis read)
I will check everything you told me to
Thanks much
Btw
Is that high on an ir mean failure soon to come
Thanks
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Old 05-06-2012, 10:51 PM   #8
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The JST-XH / IR firmware change was less than a month ago. When your Powerlab8 starts it shows the firmware version. If it say 3.31, then you are update to date. If it says 3.30 or lower, you will need to update your firmware.
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Old 05-07-2012, 05:07 AM   #9
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Gregor99

You were an awesome help
I was not at 3.31 I was at 3.30.Did the update,put one gens ace on charger just to check it out and it shows 1.1 and 1.2 readings now instead of the high #6 cell being at so high ir
So it was in fact the firmware update that was needed
Helifreak and all of it's resources and people are such a great help
Thank You soooo much for your time and help and also to the others that was working with me on solving this
I will further check it on other batteries and under different conditions as soon as I get a chance ,but it looks like the mystery is solved
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Old 05-07-2012, 10:01 AM   #10
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Glad to help.
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Old 05-07-2012, 10:16 AM   #11
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I will leave this thread open for a while just in case it may be a benefit to anyone else with a Power lab charger

Last edited by Heli,Ed; 05-11-2012 at 01:35 PM..
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