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Question about battery internal resistance meter
#11
Quote:nero1986,

When grouping 18650 batteries, I learned that their internal resistance is important. I decided to buy a YR1035 internal resistance meter. Has anyone used this device before? Or is there a different device to offer?

I have used and am using the "device" I have 4 variations of this meter. I would not use anything else unless you want to spend $4000 on a Keithley DMM7510!
As you all know I live and die by IR.

So to read all these post on the discussion of IR for high drain, low drain, IR matters , IR doesn't matter I have to chuckle to myself as yea some of you have experience with IR and some don't.

Now does anybody have (I have as of last count) 6087 cells that they have tested AND recorded the IR and V before the capacity test and then recorded the IR and V after the capacity test after a minimum of a 30 day rest.

If you do great please share this data. My guess nobody has so all this discussion is hearsay, personal opinion and possibly some experience.
There is one small clue that IR is somewhat an important factor as most but not all manufacturer include it in their spec sheet.
Now why would a manufacturer include a non important measurement like IR in their product spec sheet?
I don't know?  Why would a car manufacturer include tire pressure or oil type and weight in their spec after all who cares if we have the wrong tire pressure or oil in our car worst that can happen even if we drive it slow is blow a tire or maybe even a motor. After all who cares what the tire pressure is. Well I can tell you that I do especially after I put 4 Michelins on, dam they cost a lot.

All I know is that before I consider IR as an important factor in my harvesting strategy my harvest sheet looked like this.

And after taking IR into consideration my harvesting sheet look like this.


The difference is It takes me 5 seconds at the most 10 to test the IR and V of a cell and see if it is a good candidate .
Sure I could just throw all of the cells that I harvest into the chargers to tell me if they are good or not. To some that way of doing it is fine so be it. Let them continue to do it the way it has been done from the beginning.

I am not here to change anybody's mind just to demonstrate with research and FACTS that IR is a very important measurement to take.
In the beginning I was happy to have cells over 2000mAh come out of my testers just to discover that the cell is a 3000mAh cell and has only 70% of its capacity and eventually found out that the IR was too high for that brand of cell and I should really never have wasted my time on it.

So for those that don't care about IR and an enlightened way to harvest cells no problem stay where you are I am sure you will do just as well with or without IR. Its like the elderly man who never knew what the internet is or how to use it. If you never know about it you would not miss it. But take my IR meter away from me man there will be bloodshed.

Wolf
If 18 X 650 = 2200+mAh then we have power! 
May all your Cells have an IR of 75mΩ or less Smile
Last count as of 8/7/2019
Total Number of Cells Recorded and processed                 6149
Total Cells required for PowIRwall                                   2856
Total Cells ≥2200mAh, ≥80%, ≥35mΩ, ≤75mΩ, ≥4.12V   2760
For Info Google Drive
Not your average Wolf       
            Cool
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#12
@ Daromer,
Cells at 2-3ah that i charge with 1 amp for over 4 hours, then they are not oke and will not be in my pw.
I must admit i could have spend some more time on writing.

Cells with a odd ir, i don't even test further, thanks to the Wolfman.

@ Wolf, i would be happy to give you a copy of my data, if it is something for you.
I am not a xls pro, more a dummy, so every cell type/mfg has his own sheet.
And a max of 100 cells in a sheet to get only the proper ir for that specific cell.
You will also find data from cells that i don't even want to have, so that sheet has data for ~10 cells.

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