Twelve NEW 2400mAh 18650s, under $30?

Comfy, are these good readings? I’m not familiar with this light. Also are you saying these are good cells or not? The reason I ask is because I actually want one for my HP, so it’s probably a better deal for me than anyone.

I will have to get the one in Reduk’s link of course, but I presume they are the same.

Marc.

Still in Secaucus, NJ today (Tuesday)…

It's just a runtime comparison between an unknown cell and a known cell in fairly new and excellent condition, the INR 15Q (1500mAh).

I have a Turnigy MAX80W on the way, maybe I can figure it out well enough to get some real data finally.

Ok, good stuff. Discharge test would be excellent. Looking forward to them.

Thanks,

Marc.

comfy,

Got this pack in, but having a hard time finding somewhere to get “into” the pack. The one I have is sealed pretty tight all around? Where did you go in initially?

I was expecting that the connector would be the easiest place to start, but even that seems to be sealed up pretty good :(…

Jim

I think I had to chisel a starting point with the screwdriver, for sure it was one of the corners around the connector opening (doesn't really matter if you poke the circuit board, as long as you don't short anything). Don't remember to which side, though. I've already thrown out the plastics so I can't go back and reverse engineer it for you. Wasn't that tough, but I was using the magic pliers on them.

Hi,

Ok, got the case separated.

What I did was use a pocket knife I have (a whetstone) and run it down the seams several time, to cut some of the glue or material down in the seams. The “back” seam, the one on the opposite side from the connector was actually pretty weak, so after I had done that a couple of times, I then took a flat head screwdriver, with about a 1/4” head, stuck it into the seam and twisted. That started spreading the seam. I did that across the back seam a couple of times, then the seam kind of popped open at a corner. I separated the sides my grabbing and pulling them apart (it wasn’t easy!).

I thought that once I had the two halves of the pack apart that it’d be downhill from there…. wrong :(!! The darn batteries are in quintuples, each with the + ends all tied together with metal bands/strips and the - ends all tied together with metal bands/strips, and each quintuple is GLUED with some white stuff, really hard, to the casing.

So there are 3 quintuples in the case, end-to-end.

Struggled with getting them up. I didn’t want to stick anything in, for fear of damaging the wrappers, so I kept trying to twist the casing, and, amazingly one of the quintuples, the middle one, kind of popped out of the casing. Then, one of the quintuples on the end I was able to pull out, but the last one (isn’t that always the case?) was a heck of a time getting it out, again, just kind of twisting the casing and pulling on the batteries.

Again, I thought I was on easy street… wrong!!

Now I had 3 quintuples of batteries with each battery in each quintuple bound to other batteries with metal strips, and these metal strips were kind of wide, and I was trying to figure out how to separate the batteries.

So I did what I did previously. I took a knife and carefully going in between the batteries, tried to cut the strips.

Then, SPARKS!! And, one of the batteries started feeling a little warm.

Ran outside, carefully dumped the quintuple into a ceramic container on our driveway (kind of reminded me of a couple of other thread on BLF the last couple of weeks). Thank goodness it wasn’t raining today!

Waited awhile then took a look. It turns out, I think, that the problem was that I had nicked the wrapper on one of the batteries, near the top corner on the positive end, and the metal connector that I was cutting on the + end must’ve touched that exposed area, probably causing a short:

I eventually got all 12 batteries separated, and the metal strip things removed… but wasn’t easy, and some of the batteries still have that white stuff stuck to them.

The main things were:

1) The glue holding the battery quintuples to the case

2) The metal strips/tabs connecting batteries within the quintuples was very wide, so it hard to get in there without possibility of shorting something or damaging the wrapper at the + end of the batteries.

3) My wife is kind of ticked off at me now for this little “adventure”, so this may be the last pack for me :(. Besides, I have like 25+ 18560s now :)… And that was not counting these 12.

comfy,

How did you remove that white stuff from the batteries. I think you mentioned some chemical, but is there any “normal” chemical, something that I’d have around the house, like alcohol, that can be used to remove it?

Thanks,
Jim

Hi,

Also, a couple of the batteries sustained small nicks (very small… much smaller than the one pictured above), either on the top+ corner or somewhere else, of the wrapper. I don’t have any kapton tape or heatshrink. I had read that clear packing tape could be used to repair those, and was wondering if this is true?

The white stuff is just silicone adhesive, use a dull knife and/or fingernail. Just something that won't cut the heatshrink.

Look at my pic in the first post, with the three batches of four laid out. In that position, cut between each batch with scissors. Then with each batch, grab the tab with needle nose pliers, and roll it until it pulls the spot welds loose. Then unroll/straighten the bit you just pulled loose, get a new bite at it, and roll again. No need to separate the 4 cells before removing the tabs.

Yes 4 cells out of my 24 had spots like that at the top corners. I re-wrapped them. If the spots were down on the middle I'd say tape would be fine, but that close to the positive I'd only feel safe if they were re-wrapped.

84 cents. Get some. http://www.fasttech.com/products/1616/10001953/1140200-29mm-heat-shrink-wrap-1-meter

I’ve been meaning to get some anyway, but it’ll take at least 1.5-2 weeks to get here. Would tape be safe temporarily?

Also, for that heatshrink, is a hairdryer ok? I don’t have a heatgun.

Finally, when I order the heatshrink from FT, I’ll also get some of that kapton tape.

Thanks,
Jim

P.S. Do you think those nicks were already there on the batteries before extracting them?

Yes, the nicks were from when the tabs were spot welded, some of mine were on the inside of the group-of-four, no way it could have been done otherwise.

I don't know if a hairdryer is hot enough. I use a butane soldering iron with no tip screwed into the hole in the end, so it just blows hot air out the end. Endlessly useful thing to have on hand. (http://www.google.com/search?&q=ST250K)

I would tape up the damaged ones... and store them away somewhere safe until you get the heatshrink.

Hi,

FYI, the reviews on that heatshrink on FT says hairdryer works ok, but I understand.

Jim

Yeah, it doesn't take a lot of heat, it's easy to overdo it with the torch and pop a hole in it. With the torch cranked down low it's great, quick enough that the cell never feels warm.

Funny thing about heat, whether it's soldering, or heat guns, or welding... sometimes a higher temp keeps the workpiece cooler, because you spend less time pumping heat into it. I've ruined way more stuff from using not enough heat than from too much.

comfy,

BTW, I’m planning to try the discharge on one of the 12 tonight (one of the clean ones). Will post back. I want to try that setting to see if it doesn’t stop midway, anyway.

Jim

I've done a top-up/discharge/charge/discharge on a few of them so far (before I got distracted by the Fujitsu packs) and the numbers don't look too hot. But this whole hobby charger thing is completely new to me, so I need to play some more before I know how the numbers I get relate to reality.

Sorry about the “distraction” :)… but it was a good one, right, I hope :)?

So what kind of numbers did you get, so we can compare?

I’m doing a charge on one of them now, and then I’ll do a discharge to 3.0V (since I got help here… I turned the safety time off, and will be watching it “like a hawk”, esp. after this afternoon’s “adventure” (sparks, smoke, and burning odor).

Will post back…

Jim

I grabbed 5 at random to test but only finished 3 of them, but they did 1321, 1338, & 1340. 1A down to 3.0V. But, I haven't done discharge tests on any other brand/capacity cells to know how the numbers from the Turnigy relate to the advertised capacity.

Did you see the pic I posted in the other thread about the 'distractions'?

Hi,

No, sorry. Which thread was that? I’ve been going blonky with all of this charging/discharging stuff :).

BTW, do we know what these from the pack are suppose to be rated at (too lazy to check)?

Jim

Hi,

Re. distractions, was it post #94 on this thread (FYI - some 'new' Fujitsu laptop batteries)?

If so, that’s a good kind of distractions, right?

Also, I thought another person on the other thread just threw the Fuj/Pana batteries into their i4 charger (so less than 3 weeks)?

Jim