This pack was harder to open than my last pack due to the plastic being more brittle.
The tabs were welded in 4 spots instead of 2, and that made almost all the tabs come off poorly.
One little spark while taking it apart due to simultaneously clipping multiple wires at the pcb. Oops.
Initial voltages: 2.267, 1.985, 2.109, 2.110, 2.268, 1.987
http://www.ebay.com/itm/330866686790
Only 2 left, $15.59 ea. There are other batches in the store but at higher prices - price seems to have no relationship to date codes or voltage, etc. as the seller routinely raises & lowers prices on the listings with no apparent rhyme or reason.
I just bought 6, will update here when they arrive. Hope these have the same innards as the black versions...
I have half a mind to email the seller and tell him what’s going on. He probably — as I would if i was selling them — thinks people are using them for computers, which they are not. So he raises the prices to make a couple extra sheckels but doesn’t realize that makes them not a financially feasible risk for pack poppers. Because of the older dates and fasttech competition. But you never know what a buyer will think when a customer contacts him. So I haven’t contacted him.
>>>>>>Hope these have the same innards as the black versions…
I ordered a white one also. As I remember from the Panasonic 2900 pack-cracking fest a a while back, the white acers were MUCH easier to open. Frankly, I would not mind at all getting some 2800 LGs (also korean made). My tan-label 2200 and 2000 LG pack pulls have been great performers.
Armed with my lux meter and DMM, I find these Samsung 2800s edge out the Panasonic 2900s when being mercilessly pummeled by high-demand high-amp drivers, in the 4-5 amp range.
The 2800s start at a slightly lower lux BUT they maintain a steady lux output better than the 2900s. For example, in one souped-up DST, the 2900s start at 82k lux, and then spiral down over 30 seconds or so to 72k lux, where it holds for a couple minutes and then slowly spirals down … giving me maybe 10 minutes of highish output. The 2800 Samsungs start at about 72, drop slowly to 68ish and hang there for 5 minutes, staying longer in the 60k output range than the panasonics. The down spiral is much slower than the Panasonic even though the Panasonic is initially higher for like 45 seconds or so. The Samsungs give me maybe 20 minutes of highish output. Once again, YMMV depending on what light you use, but my quickie tests were consistent in my 4-5 amp lights.
In medium-high output lights, in the 3-3.5 amp range (aka stockish nanjig drivers), there doesn’t seem to be much difference in outputs. Both samsung and pan 2900s do very well.
In my tests with 4a-ish lights, the red purple-ring NEW Sanyos from Fasttech work the best and output the highest for the longest. Nothing beat ’em. But the Samsungs are not shabby. Samsung 2600 pinks also do well with the higher amp lights. The ones I tried anyway. If anyone else has a lux meter, I would love to see what numbers they get. Yes, I am aware of HKJ’s wonderful charts, but real-world tests can only help data reliability.
Hope this helps.
Is there a way to trick a hobby charger (Turnigy MAX80W) into charging these 4.35v cells? Maybe by manually changing the calibration to read .15v lower than actual, if it has that much adjustment?
Are you aware Fasttech sells cheap 4.35 volt chargers?
According to HKJ’s tests, the full charge light goes green at 4.3 volts, and trickles up to 4.35 volt.
I'd rather find a way to use the charger I already have if possible, instead of buying a new charger for each type of battery... that's why I got a hobby charger in the first place!
The MAX80W only has menu options for LiFe>3.3v, LiIo>3.6v, LiPo>3.7v. Of course I wouldn't be surprised if there's a hidden menu somewhere I haven't found yet.
Ah gotcha.
Yeah I am still trying to decide which hobby charger to get, but I also like having a variety of chargers so I can have lots of batteries charging at once.
My iCharger 106B+ has a default setting in Lilo of 4.10V, adjustable to 4.20V. In Lipo default setting, it’s 4.20V, adjustable to 4.30V.
Discharge current range from .05A to 7A
http://www.jun-si.com/UploadFiles/iC106B+\_en.pdf Owner’s Manual
I have a question.
I’m looking at the construction of these cells and see that even when a cell is ‘flat-top’ there is still a raised pedestal on the + end that is simply surrounded by a ring of plastic. Aside from the loss of verifiable mfg data, what is wrong with simply removing the factory wrap, removing or shaving down the plastic ring, and then applying new shrink tubing to the case? Does the plastic ring hold the cap on the end of the tube (as I type this this seems to make sense as I cannot think of a welding process that would not damage the cell itself).
The metal can is crimped at the top, the outer wrap and anything else is just protective. There's a plastic insulator between the cap and can, but you'd have to destroy the cell to get it out, it's inside the crimp.
Spot welding is a very localized heat, and with the tiny size welds used on battery tabs I wouldn't be surprised if you could hold the metal in your hand while it's being welded and not feel a thing. Very high amperage in a tiny localized spot only takes a fraction of a second to get the two pieces to fuse.
Just add a small dollop of solder if you really can't find any other way to make them work. Use flux. And as The King Of Pack Pulls said earlier, load up the iron with solder, let the iron recover from melting the solder so it's as hot as you can get it, then lay it on the cell and, at most, count to two and remove the iron. If you do it the same way you solder big fat wires, the cell will vent at best, and at worst it will melt the insulator between + and - and then you very likely have a very unpleasant fire to deal with. Practice on old dead alkaline batteries, that really helps. If you get it wrong on alkalines they won't try to kill you as punishment for your mistakes.
>>>>> load up the iron with solder, let the iron recover from melting the solder so it’s as hot as you can
>>>>>>get it, then lay it on the cell and, at most, count to two and remove the iron.
>>>>>>>If you do it the same way you solder big fat wires
I guess I didn’t explain myself. DO NOT heat the positive pole. Do NOT touch the positive pole with the pen tip. Just get the tip close enough to the pole so that big drop of solder flows onto the pole. Immediately move the pen away and put it in the stand. You’re done with it.
Count to three or four, and THEN you can touch the blob or move the battery. Once again, at NO time, heat the pole. The positive pole metal structure quickly disspates the heat from the solder blob.
I will say that this is with old-style 60-40 lead-tin solder. Not the new lead-less solder variants. And I use a weller station. I don’t know if you could maintain a big drip of solder on the pen tip with the smaller pens that plug directly into the wall and don’t have a separate power supply like the weller and other station-type soldering setups.
Hope this helps.
@ comfychair: So I could theoretically remove that plastic ring at the top without breaking the seal of the cell or damaging its integrity?
@Ubehebe: I have my dad’s old Hexacon TOT-1002. Waiting on a new tip for it but I have used it in-past and it works. Nowhere near confident I could do the solder blob trick though. 
There is not enough stuff on top of the cell that can be removed to transform a flat top cell into something with dimensions similar to a button top. The insulator ring on the outside of the cell but under the wrapper is very thin, about the same thickness as the wrapper itself, and the other insulator is inside the crimp between the cap and the shell and can't be removed without unrolling the crimp and destroying the cell. This one inside the crimp is the one that can be damaged by too much heat when soldering.
If you can't learn how to do the solder thing your only remaining choices are to either modify the light/lights to work with flat top cells, or buy button top cells.
Practice.
>>>>>Nowhere near confident I could do the solder blob trick though
Just practice flowing 20-30 blobs onto something that will suck up the heat fairly fast, like the side of an old pair of pliers or a big metal washer. You’ll get the hang of it.
Like I said, my first attempts at this weren’t pretty but they worked just fine … well sort of. I was trying at first to imitate a raised top by getting a small round-ballish blob on the positive pole. But if you do it that way, the little ball gets caught all the time in battery springs, especially the nanjigs. So that’s why I changed to the “lump” method. Also the small balls tend to scratch the gold contact plating on the driver. The lumps don’t scratch them.
Hmm. Damn. Well if there isn’t enough weld material left on the + poles I might not have a choice. I took a closer look at the Panasonic 3400’s I have in front of me and you’re right, the insulator ring is thin. I’ll have to see when I get it open. A friend is giving me a 10.8v 5000mAh Li-ion MacBook battery to play with. So if i crack it open and indeed there are round metal cylinders in there either I’ll get some practice or the local fire department will get live practice on a residential chemical fire.
>>>>>some practice or the local fire department will get live practice on a residential chemical fire.
It isn’t just the fire. It’s the fumes. Suppsosedly, a li-ion fire creates hydroflruoric acid fumes. Or more accurately your lungs do when they come in contact with another gas, I forget which now.
You do NOT want to breathing that stuff. One whiff and that’s all she wrote. In fact, somewhere on CPF is the very scary story of a guy who had a li-ion battery blow up (not my story; mine was in a charger; his was in a flashlight). Anyway, if I remember correctly, he badly burned his lungs and was a mess, in and out of the hosital for weeks. You do NOT want to open up a li-ion cell. If it catches fire, it spreads this black gummy tarry stuff all over your house. It is nearly impossible to wipe up because it’s gooey. I know because I had a battery blow up. Trust me, you don’t want it to happen. 
+1 I also remember reading that story. In short: the damage caused by the gas produced is long-term and not only temporary. That man now has to live his life with an inhaler close by, he also has severely reduced lung capacity.
Just when I was gonna try my luck with a pack, the seller seems to have caught on (or maybe just thinks there’s a huge demand for these packs). He has only lower rated (2200 mAh) or 3-cell packs listed around $15.xx now.
I can’t imagine that us folks on a ‘budget’ forum will pay ~$10 more for the same item…
Suggestions on how to smooth out the weld(?) spots from the terminals? The (weld) remnants are rather sharp and may cause less than full contact.
>>>>> smooth out the weld(?) spots from the terminals
If you read back in the thread, you’ll see how I talk about using a drmel on them. Do NOT cut into the metal on the neg pole (battery bottom), it is very thin and easily ruptured.