Yes steepdrop, let us know what’s in there when you get them! 
I received the PC batt. packs , I have no way of checking amps or mah ,but I can give You all the date code
top row : GO99
2nd.row : 3K4A1
They came well package and are look New
ICR18650-28A
SAMSUNG SDI
933 wish I could be more help
Newbie at this.
That helps a LOT! So they were made in March 2009…hmmmm, so 4 1/2 years old. Let us know how they hold a charge if you don’t mind. Thank you, Mr. Steepdrop!
From page 2...
Date codes are not decodable with the information we currently have.
Did you see this? v
Yes, and those markings UNDER the wrap are the ones that fail to decode using the info in the .pdf and restated here. It fails.
For instance:
Line 1 : 1128 —- 1st digit: line number ( “1” means Line No. 1)
2nd~3rd digit: Model Name (“12” is INR18650-15Q)
4th digit: Year ( “8” is 2008)
Mine read: K2BB - makes no sense. What year is 'B'? Shouldn't a 15Q have a model code of '12'? Where's the '12' on my cells? Why is the Model Name code on my 15Qs '2B'?
If it doesn't work on one cell, especially for the actual cell the actual .pdf pertains to, it's not reliable to use on others even if it appears to show a valid plausible date.
So even if you decide to ignore the stuff that doesn't make sense (line numbers aren't numbers in the printed code but are instead letters, the Model Name codes don't match) you're still left with this: Say they changed to letters after year 2000 like with automotive VIN numbers. Is year 2000 a '0', or 'A'? My cells with a year code of 'B', is that 2001 or 2002?
AND, on these purple 28As, the first line is J9A2. If they switched to letters after year 2000, what year is '2'? 1992?
Looks like I have the same ones you do….
J9A2
62A71
Yup, I’d rather ignore what doesn’t make sense and say it was made on June 2, 2012.
I might be wrong.
But like I mentioned earlier, they can't be 2012 cells inside a pack built in 2010.
You’re right. 
I have bought three 6-packs, and all have come charged to a perfectly respectable 2.2-2.54, and all are purple Samsung 2800s as expected. Like all new li-ions, they pop up to about 3.6 or so after about 1 minute in an Intellicharger or equivalent.
[/quote]
Thinking that these cells should have arrived charged to 3.8 volts, or so. 2.2+ volts would be too low for these cells, and should indicate that they are ruined. Good that they pop up to 3.6 volts when put on the charger, but still not good.
William
It's not 'not good', they are new cells that have never been charged. If these were used and had those voltages it would be a completely different situation.
I would not mind so much of the age of the cells. I had so many as old as 8 yr. olds and never had a problem. What is more of a factor is how that cell ‘lived’ its life when it was still in service. Prolonged exposure to high heat, the number of cycles it went through are more of the things that I will worry about. I have not yet encountered an unused, unsold battery pack, no matter how old, turning out useless.
You say that ..and I have had good luck with cells that were unused and had lower voltages too .....But having just opened an unused pack where every cell tested 3.76v I have to believe we all want themto be at optimal lithium-ion sleepy voltage
I was happy to see all of them at exactky the same 3.76
I find it interesting that the cells that measured 2.60v and the cells that measured 2.95v took the same mAh to bring them up to 4.20v on the hobby charger. In a new never used uncharged cell the resting voltage is an indicator of precisely nothing at all.
I STRONGLY STRONGLY+ advise against heating the positive pole on these batteries AT ALL. For any reason whatsoever.
Heat can destroy the usefulness of the battery, and it can also melt the catalyst bag inside, precipitating a catastrophic vent.
The solder adheres just fine without applying ANY HEAT to the positive pole. Simply melt the solder on the pen tip. NEVER on the positive pole.
Rough up the positive pole with a dremel or an abrasive. Apply extra flux if needed. I never need it. I use fairly common kester 60-40 rosin core lead tin THIN solder, .040”, sn60pb40 #66/44.
Keep adding solder to the growing drip (ball) of solder on the pen tip. When it is about to drop off from its own weight, simply transfer it QUICKLY to the positive pole. Do NOT touch the pen to the pole for longer than the millisecond it takes to transfer the blob. There is NO reason to preheat the pole. The blob retains PLENTY of heat for a second or two and will spread out by itself just fine. If it doesn’t spread out like the pictures, you didn’t use enough solder and the drip wasn’t big enough.
Preheating the pole risks damage to the battery and to the user. The jelly-rolled bag and catalyst inside the cells is EXTREMELY sensitive to heat.
I just took an old cell and preheated the pole for two seconds and then four seconds. Then I tried to touch the pole and almost fried my finger off. Two-four seconds is WAY WAY+ too much heat transfer for a solder station like the Wellers.
Using my method — without preheating the pole — you can touch all around the positive pole without burning yourself, immediately after the solder has been applied. The metal will be warm but not hot, not even close to being hot.
I have made solder blobs on hundreds and hundreds of cells and NEVER had to preheat the pole. Once again, preheating the pole is dangerous and NOT needed.
I don’t want to see anyone hurt. If you are unfamiliar with soldering, applying solder blobs to batteries probably should not be your first project. Practice until you get it down, and then try it. Practice on old batteries or the side of pliers or some heavy heat-absorbing metal piece. DO NOT keep heating up the battery until you “get it right.”
Finally, we all like to make things look nice, but esthetics should take a back seat to function and safety here. ANY slightly raised blob of solder on the positive pole will do the job, as long as it’s reasonably smooth and centered. If it comes out uneven and ugly, do not redo it with more heat. Just move on and do the next one. After a while, you will get the hang of it. Once again, do NOT keep applying heat to correct esthetics. Sculpt the messed-up solder ball with a dremel or emery board or file or whatever
If you feel uneasy about your soldering skills in applying blobs to positive poles, you probably haven’t practiced enough. It’s really not that hard, but it does take some practice.
Hope this helps!
Comfychair do you have a hobby charger ?
Steepdrop what were your resting voltages ?
WTG Ubehebe ...I was wondering when you'd chime in about soldering on to batteries .
I love this thread ...
Yes, Turnigy MAX80W. http://www.hobbyking.com/hobbyking/store/__11341__turnigy_max80w_7a_lithium_polymer_battery_charger.html
I use a DC-DC converter to do the 4.20v to 4.30v part - manually adjust the voltage across the cell to 4.30v, when it rises to 4.31v I turn it down to 4.30v, repeat until it no longer increases above 4.30v.
So just to report I got my two packs open this weekend. All came out between 2.6 and 2.9.
I did a discharge on the first one tonight. From 4.2 to 3.4 it gave 2125mah at a 1 amp discharge.
I had to shut it down to go to bed, but all signs point to these being brand new cells.
I’ll run a full test tom. Now to find a good 4.3v charger.
Thanks for the find!
This thread is getting too long, excuse me if its already gone over. But I did look up some info, and on several sites the discharge is rated at 0.2C, which is strange. I’m certain they have to be used with a higher discharge rate than .56A in the applications they are used for (pretty sure the laptop isnt running on .56A for almost 6hrs!!)… so I wonder what this really means? And what is the real safe discharge rate, especially as an “ICR” battery, known to us as “high discharge rate” cells having such a low current listing. http://www.samsungsdi.com/battery/cylindrical-ICR18650-28A.jsp