Internal resistance is the factor,
that will determine the overall health of a lithium ion cell.
I typically see the IR values increase substantially after 5 years,
whether the cells are used or not.
IR increase will increase heating of the cell while charging and discharging.
Panasonic & Sanyo cells seem to hold up the best in my testing.
LarryDFW
P.S. Mitro noticed a decline here with 1 year old cells vs. new ones:
Graph for Old vs New
You are right, however that 2572mAh put into the cell could also be low. We don’t know how fully charged the cell was in the first place.
Bottom line is we need, like you said, a discharge test. I can’t do it, all I havv is my real world test with my FandyFire Warrior as in the first post.
@LarryDFW I’m not trying to arguing the fact that li-ions do degrade over time. Its just that they are several variables that will determine how much they degrade over time. IR values do general show how much the cells have degradation. The cells in ohaya’s thread seem to all have typical factory IR values even though when we received them, they had a measured voltage of around 2v. I was told and had read many times that a cell in that voltage range would have been junk.
I tried to do my research before jumping in on that battery pack deal. I could not find any info where someone had a brand new cell that had never been used setting for 4 years or so and then tested it afterwards. Most people after all use their batteries once the receive them. Once a few had been tested, I had to see this for myself, so I jumped in on the deal. Sure enough their as though they had just been made. That’s the reason I have two of those setting on my desk self discharging, testing purposes. There has to be some thing going on with a cell that has never been used that prolongs its life even with it self discharging below a safe level. I should have left one as is, uncharged just to see what happened in a year or two.
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The link you gave comparing new and old battery doesn’t really consider in the variables in my post above. To be fair, they would both have to be unused and the older cell’s would need to be stored at a cool temp. Correct me if I’m wrong, I don’t think they where unused as he doesn’t really say, I would assume he used them. The packs we received and tested where unused. We know if the cells aren’t abused by the variables they last longer, what happens if they have never been used after 5 years. So far they act like new in my experiences. More time will tell.
Can’t believe that life was possible without a full compliment hobby charger. Have used mine on almost all chemistry batteries and the load function is the best real world test. Wouldn’t bother with anything less than one with a minimum of 5A. IMHO
Charging the set of cells seems to indicate they do have some built up resistance.
Charging in my i2 and i4, initially put them to 3.8v and then I had to stop because I could no longer monitor them for the day.
Starting again today, after about 1h 45m on the charger the cells are up to 100*F, and 3.89v.
My other laptop pulls and brand name cells don’t get nearly this warm.
… safe to continue charging?
Just a heads up to you all. Thank you so much for the interest in our batteries. It seems this is working out nicely for both of us. We are down to one unit of the NB800AA new in open package. It looks like you all are buying up the PA3332U-1BRS -FS Toshiba battery as well. At the current sales trends I would guess maybe 3 weeks worth at best. We do also have our own site at www.inandoutcomputers.com I do not believe we have anything there that is not on eBay but by all means take a look at our site. We also get tablet batteries from time to time. Not sure if those are of any use to you all ? I think part of the reason you all may be having pretty good luck with these old stock but new batteries is the fact that our warehouse is quite cold. It seems that helps preserve these cells. Just an FYI we do have some more bulk packaged NB800AA that are still genuine originals but they are not in retail packaging. We do not have these up on eBay. If you are interested just shoot me a PM and I can do a direct order for you at the same price.
Corey
Thanks Corey. I'm looking forward to my third order with you.
I have tested many cells with 2 VDC starting voltage that had very good IR readings.
IR is easily the best indicator of cell health.
IR Ranges for 18650 Cells that I use:
50-100 mOhm - Excellent (55mOhm new Panasonic 3400)
100-200 mOhm - Good
200-Up mOhm - Poor (will overheat, may lead to thermal runaway)
High IR is only dangerous when charging or discharging,
so that is when you have to check for heat rise.
LarryDFW
Just got my Pink Samsung 2600's for $10, same pack in the OP and details posted earlier. Got to clean them up and charge em now. Price is up to $15 now, looks like. Thanx Corey!
I just got my order and eagerly took my 2 10$ packs apart to find pink samsung 26 c. All came in at over 2.5 volts and have the fist 4 in my I4 charger
Thanks Cory
I got the pack in today. Quick summary don’t waste your money, two bad cells and unkown brand.
Brand - ASO?
Capacity - ?
Cell Voltages - 1.37, 1.37, 3.36, 3.36, 3.44, 3.44
Anyone know which cells are in this pack http://www.ebay.com/itm/New-Genuine-Toshiba-M30-M35-Laptop-Battery-PA3332U-1BRS-/171249219347?pt=Laptop_Batteries&hash=item27df3fb713
I bought 3 of these packs and got the green sony batteries in all of them.Great batteries
Yesterday somebody bought 12 packs!
3 of which pack? link please
I bought these cells below (in and out. store ebay)
9 salmon colored cells LGDB2118650
this link gives info:
I wonder how these compare to the pink Samsung 2600 and green Sony 2600. I want to order another pack from the same seller but I’m not sure which one to order. Any chance one of the packs he is selling contains gray Panasonic 2900’s?
toss the 1.37 and test the others.might be pure crap might be ok.iirc thats geil energy.
What is the problem with protected and unprotected cells?
Do they blow up after they are full drained?
I’ve always bought protected cells why unprotected?