New purple Samsung 2800mah unprotected 18650 batteries for $2.68 each

Will that also explain why some laptop batt packs are 3-series but is 10.8V and some are 11.1V ?

Looks like a good deal for large pack builds. What dates of manufacture are you guys finding on your packs?

>>>>What dates of manufacture are you guys finding on your packs?

Got me. No date on the pack, and even if there was, that would only be ball park.

Date code on the cells themsevles are sometimes three numerals, sometimes four, sometimes alphanumeric.

I poked around on the the interwebnet and couldn’t find anything definitive for samsung. Might be in hex format, might not be. First number may be the year; but also might not be.

Please let us know if you figure it out.

Some of my date codes:

954
2C51
2C44
2C63
2CC5

More searching turned this up from a product sheet for the samsung 15q 18650 on how to descipher the date code.

  • begin samsung samsung date code description

Model and Date code Marking : there are three lines on the cell tube as follows.
Line 1 : INR18650-15Q —- Cell Model Name
Line 2 : SAMSUNG SDI —-Cell Maker
Line 3 : 096 —-Part number

Lot marking : There are two lines on the cell metal can as follows.
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)

Line 2 : 4E1C5 —- 1st digit: Month ( “4” is Apr. ; A is Oct., B is Nov., C is Dec)
2nd digit: Date (“E” is 15th day ; 1, 2 is 2… , 10 is A, 11 is B…)
3rd digit: Serial No. of winding
4th digit: Reel No ( “C” is C reel ; A is A reel, B is B reel, … F is Freel)
5th digit: Winding Machine No. ( “1” is No.1 winder)

  • end samsung date code description

Source is:

Some of my mystery date codes:

954
2C51
2C44
2C63

Some creative guesswork (using ONLY the first three numbers) would mean that 954 is 2009, May 4. Using the first three numbers makes some sense with the description as the fourth number is the reel number (?). Whatever the h a reel number is.

2C51 = 2012, Dec. 5

2C44 = 2012, Dec. 4

2c63 = 2012, Dec. 6

Hope this helps!

Argh! What a PITA trying to decode dates. They must keep changing nomenclature to confuse people. Thanks for the great detective work. Sorry to put you through all that.

My new cells from fasttech are 2D14. So D=2013, C=2012,…

>>>>>My new cells from fasttech are 2D14. So D=2013, C=2012,…

You got me. It’s totally confusing. For 2D14, I was thinking 2 = 2012; D = who knows what month; 1 = 1st of whatever month (“1, 2 is 2… , ”)

But I am totally guessing. The thing — to me — that throws the whole thing off is they say the 4th digit in the first line = “Year ( “8” is 2008)” But 4th digit in that line — assuming it’s the “first” line — is 4. That would make it 2004. No way were they making 2800mah li-ions in 2004. Or have I totally bulloxed the whole thing?

AIEEEEE!!!

I just ordered a pack from them for $16. Cells are Korean so we should be good to go.

I positively 100% figured out the samsung date code mystery if anyone cares.

And I am a dummy. I looked in the wrong place!!!

When cleaning up another six cells today, I noticed that there are BARELY LEGIBLE numbers UNDERNEATH the wrapper, printed on the actual metal battery can. DUH!!! as you may remember, that’s exactly what the Samsung date code explanation says: “There are two lines +ON THE CELL METAL CAN as follows…” DUH!!! The caps are mine. It’s on THE CAN. NOT on the wrapper.

These are barely readable through the wrapper but they are definitely TWO lines in the the exact format cited in the explanation, and they are now easily translated. Here are the two lines from one of today’s batteries:

G099
5O9D2

Okay, so the last number in the first line is the year. in this case 2009. That’s the important one. These batteries are from 2009, not the best date possible, but not the worst.

Second line:

First digit = 5 is the month, so May.

Second digit is “O” (not a zero, but the letter “O”), which is 25 (directions say “E=15, so count up from there: F=16; G=17, H=etc.).

So it’s May 25, 2009!!!

HOORAY!!! I figured it out.

the 3rd, 4th and 5th digits don’t really concern us. But they mean: 3rd digit (serial number of winding = 9); 4th (Reel Number = D); And 5th number is the winder machine used, number 2 in this case.

Man, you need a degree in cryptology to figure this out.

Good show, Ubehebe !

Wonder how good 4-year old Samsung is.

(No Eneloop warranty information at Amazon.)

[EDIT]
Sanyo Eneloop warranty is 1 year.

>>>>>Wonder how good 4-year old Samsung is.

Good point.

Before I knew what the dates were, I took these; put em in a light with a 4-amp driver and shined the light on my lux meter to see how well the light output held up. Did the same with the new 2012 ones from FT. I can see no difference. After a minute, both had settled in at 48k lux and were hanging on.

After 30 minutes in my test light …. The 2009 Samsung was actually slightly higher than the 2012 Samsung at 3.94 volts vs 3.89 for the 2012 one. So I am sure there is a difference. How can a 4-year-old battery work as good as a new one? But I can’t see any difference. Maybe they drop in voltage quicker in the lower range that we don’t use in lights? Say, down around the 3.50v area? Got me.

Remember now that I have 300 batteries here and have probably processed 500 batteries over the past year, 200 of which I didn’t keep because they didn’t hold a charge or the votage dropped too fast under load. So I kinda have a feeling for bum batteries. As far as I can see, these are not bum cells. But I DEFINITELY would add a YMMV. Maybe I got the three best 2009 Samsung battery packs and all the rest are junk? Be interesting to hear what the others who bought them think.

Well I decided to order one of Fasttech’s cheap 4.35v chargers and a pair of LG18650D1 batteries ………These Samsungs should be fine at 4.35

>>>>Well I decided to order one of Fasttech’s cheap 4.35v chargers

Let us know how it works.

Man, that extra .15 would take some of my lights into the stratosphere, especially the L2s. I can really tell the diff in output in many of my L2s when voltage is 4.2 vs 4.0 and lower.

Will most single-cell li-ion lights handle 4.35 volts? I have so many (and also many modded), I wouldn’t even know where to look for trustworthy specs on my lights for top voltage.

bdiddle - Youd be overcharging the cells by a good amount @4.35V and with an uncertain outcome. If it were me, Id probably rethink your recharging strategy.

Ubehebe - As with all 18650’s, the voltage sag is nearly immediate above 1A, so you probably wont notice any differences.

Check out HKJ’s excellent cell comparator:
http://lygte-info.dk/review/batteries2012/Common18650comparator.php

General opinion seems to be that lithium cells usually go around 5 years (if well taken care of) before they might possibly take a turn for the grave. Some go longer, others not. Id say that @$2.68 each, and given Ubehebe assessment, they seem to be a great buy.

It would be nice if someone could discharge test a few of these with a hobby charger to confirm capacity. Id love to see a 3A discharge curve.

I’ll just remove the batteries at 4.3v

But don’t the companies normally say 4.2v +–5?

>>>>As with all 18650’s, the voltage sag is nearly immediate above 1A, so you probably wont notice any differences.

Still, I would like to try a 4.3 or 4.35 battery actually charged to those specs to see if they do make any perceivable difference in light output. Have you tried one yet?

Yes, and there is no difference in the initial turn-on that I have observed with any of my flashlights. Voltage drops almost immediately while under load. Have you had a chance to check out HKJ’s comparator that I linked? Check out the discharge curves of the Sanyo UR18650FM and the higher voltage ZT’s. They sustain voltage the longest above the critical 3.5V demarcation throughout the discharge curve. Most single celled flashlights will benefit from these cells. Still, the price of the Samsung 2800’s is amazing; considering that for their age, they still seem to sustain high amperage demands.

Has anyone had a chance to discharge test these for capacity yet?

Was it this one?

http://www.fasttech.com/products/1421/10000969/1343600-polar-435v-21865017670-lithium-li-ion-battery-char

Sort of depends on how the batteries were stored etc. A new unused pack that has 3.8 volts and is stored correctly My guess is it will be perfectly fine , My revrend jim panasonics are still great batteries and they are much older than 2009.. I'm guessing that 5 years from the date you start using them is a more acurate assumption .

i have some very old batteries that came from a very old laptop that still suprise me how strong they are ( orange panasonics ) i think they just were from an old unused pack .

Pack in the OP has been relisted at a higher price, $24.98... guess it was getting too popular. :)

Any idea if these have the same cells?

http://www.ebay.com/itm/370749477282

http://www.ebay.com/itm/370749474174

http://www.ebay.com/itm/330866686790

http://www.ebay.com/itm/370739547155

They're all using the exact same pics, I'm assuming they're all the same but just listed at different prices hoping someone buys without finding the cheaper ones?