*How To* on unwrapping laptop packs?

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tallboybass
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*How To* on unwrapping laptop packs?

Where could I find out how to get in those darned laptop packs without blowing stuff up? There IS a right and wrong way to do it isn’t there?

comfychair
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Start on either side of the connector and pry open a small spot with a pocket screwdriver, open it big enough to fit the tip of some outside retaining ring pliers, stick 'em in, and squeeze.

http://oi45.tinypic.com/2073qqe.jpg

Use a stick or wooden dowel as a wedge to hold it open, move the pliers along and squeeze, move the wedge, squeeze...

The cells are usually glued into just one half of the plastic case with a white silicone caulk-like stuff. It'll come loose without tools, just pick one end and gently lift the cells and keep pressure applied. The silicone stuff will tear loose but it doesn't pop loose all in one go, just keep steady pressure on it.

Once both halves of the case are gone, remove any tape protecting the wire to tab attachment points, or at least all the ones that are accessible - sometimes these things have to be done in stages due to the way everything is packed in together. Start at one end of the cells and snip the wires from the cell tabs one at a time (you might be surprised, but some folks will think they can save some time by trying to snip two or more wires at a time. Don't be one of those people). Do it in an organized way, so that you can keep each wire safely isolated from everything as you snip the other wires. An especially paranoid or clumsy person might put a bit of tape over the end of each wire as they are cut free.

When you're down to nothing but the cells, bend the pairs/triplets/quads away from each other like an accordion, and cut the straps between the parallel sets with scissors. Then peel the tabs off the cells with needle nose pliers - grab and roll like opening a canned ham. Then knock off any sharp bits left from the spot welds with a small round-end bit in a Dremel.

http://75.65.123.78/Dsc05934.jpg

FMcamaroZ28
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Oh, and do it outside.

tallboybass
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Wow Comfy, thanks yet again! That helps immensely!!

You too FM… Wink

tallboybass
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Is there ANY point in opening up a 2-3 year old pack that doesn’t hold a charge for more than 15 minutes? I guess maybe some of the cells might be good, or no??

comfychair
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Yeah usually it's only some of the cells that have died, and a few will be marginally usable. But the 'good' ones are just as old as the dead ones and have been worked just as hard, it's really not worth the work to get cells with so little lifespan left.

It's like driving your car 120,000 miles until it starts misfiring, and then only replacing the spark plugs worn enough to cause the misfire. The others are just as old and just as worn and the labor to replace one is the same as the labor to replace all of them...

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tallboybass wrote:
Is there ANY point in opening up a 2-3 year old pack that doesn’t hold a charge for more than 15 minutes? I guess maybe some of the cells might be good, or no??

After having just done that with an ancient Inspiron 6000 and a somewhat-old Latitude D620, both of which made error lights and could not keep their laptops ON for a moment w/o AC power, I can say YES!!!

Rip the pack apart carefully (I managed to hit 3 (three) shorts simultaneously on the Inspiron pack, but the smoke was just from the red plastic covers melting — I won’t use those) because they weren’t made so solidly back then, and measure the V. If any have a full charge, use it/them, down to the point the charger would bring them back up (3.something depending on the charger) then charge them.
Most won’t have a full charge. Charge them, but in any case pull them and toss them if they get “hot” (YBTJ) while charging. Some will count the V down as you read it (weird to watch) to some ‘undervoltage’ that doesn’t seem to hurt anything. Just recycle those without further concern, they’re toast. If it reads some 4.x V but won’t light your light, it’s probably one of these. Oh well. Sometimes your local recycler will get whole packs & will be happy to trade… Just thinking out loud…

If you get one or two (or 9 total, out of both packs) decent batteries, guess what? It’s all free! I honestly don’t concern myself with anything more than “is this one charged, or has it been used?”… It’s fun (to me, but I’m weird), when we’re out and my friends’ flashlights run dim, to be able to just produce a battery from a pocket for them…

Likely scenario: You’ll get most of them working, they’ll have some decent-but-short runtime, and you’ll give them away.

Worst-case scenario: You make a bad short, cause a fire, post a viral Youtube video! What’s to lose?

Dim
PS: Be sure to turn on a camera! I have only memories of this:

“There is no darkness but ignorance.”

photon1k
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I’ve harvested several packs now and the hardest part has allways been getting the two halves of the outer casing separated, especially at the beginning, when trying to get the crack started. That has just gotten much easier with the suggestion to use outside ring pliers. Thanks for the tip Comfy! Smile

tallboybass
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Wish I’d had some of those pliers…mine went ok, finally got’em out, but there was some scarring.

What does it mean when 2 of them read 4.15v and 4 of them read 4.05v??

Should I try them in a light or will it blow up?! Wink

TheGloriousTachikoma
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tallboybass wrote:
Wish I’d had some of those pliers…mine went ok, finally got’em out, but there was some scarring.

What does it mean when 2 of them read 4.15v and 4 of them read 4.05v??

It means they’re relatively fresh and you need to make sure to pair the cells in your i4? Smile

tallboybass
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This is a pack that wouldn’t operate a computer for more than 10-15 minutes…ONE of them has to be bad, right?

photon1k
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One or more of them is bad, in this case bad meaning different from the others. The protection in these packs is very picky. It has to be to protect the manufacturers from liability claims. Wink

The two at 4.15 should be treated as a group, and the other four as a different group – don’t mix the two groups. If you test them you will likely find a difference in capacity and internal resistance between cells in the two groups. That is what tripped the pack’s protection. I think you will find that all of those cells are usable.

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Amazing, I just cleaned them up and they all work in my S3! I see what you’re saying P1K, I’ll mark them to denote the groups. This pack is dated 12/2010 so they’re coming up on 3 years old, with a cheap meter and an i4 is there any way to discern capacity or anything else that might be useful?

tallboybass
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They look better than this now, but the wrappers got damaged a bit. Smile

TheGloriousTachikoma
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As bad as the tears on those wraps look I want to suggest you strip the wrap and apply new shrink-tube over the cells. That looks like a short waiting to happen.

GottaZoom
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tallboybass wrote:
They look better than this now, but the wrappers got damaged a bit. Smile

http://budgetlightforum.com/node/19095

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95% of those nicks will all but disappear with a few passes from a heat gun. I wouldn't strip & re-wrap just for the damage shown in that pic.

The silicone caulk junk in the white Acer packs is a lot tougher than what I've run into in other packs and a few of my cells had the wrap stretched out pretty bad but not torn. I went over them gently with my hot-air-blowing butane pencil iron and all the bad spots went away.

 

edit: OK, 4th one down from the top I would re-wrap, due to the nick at the top corner. The others will be fine after a little heat.

"A short" in this case will only be between the - and the light body which is the exact same 'short' the tailcap switch creates to make light come out the shiny end. Nicks in the wrap on the sides of the cell body will never be able to make electrical contact with the body of the light unless there's a corresponding burr on the ID of the tube, highly unlikely.

photon1k
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tallboybass wrote:
Amazing, I just cleaned them up and they all work in my S3! I see what you’re saying P1K, I’ll mark them to denote the groups. This pack is dated 12/2010 so they’re coming up on 3 years old, with a cheap meter and an i4 is there any way to discern capacity or anything else that might be useful?
Unfortunately an i4 won’t help you measure discharge capacity. A bit tedious, but you can measure relative capacity by discharging them down to a particular voltage in a light — a lot of work for very little information. With a DMM and a resistor you can measure internal resistance.
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comfychair wrote:

95% of those nicks will all but disappear with a few passes from a heat gun. I wouldn’t strip & re-wrap just for the damage shown in that pic.

The silicone caulk junk in the white Acer packs is a lot tougher than what I’ve run into in other packs and a few of my cells had the wrap stretched out pretty bad but not torn. I went over them gently with my hot-air-blowing butane pencil iron and all the bad spots went away.

 

edit: OK, 4th one down from the top I would re-wrap, due to the nick at the top corner. The others will be fine after a little heat.

“A short” in this case will only be between the – and the light body which is the exact same ‘short’ the tailcap switch creates to make light come out the shiny end. Nicks in the wrap on the sides of the cell body will never be able to make electrical contact with the body of the light unless there’s a corresponding burr on the ID of the tube, highly unlikely.


I agree with Comfy, the battery body will only contact the part it is supposed to contact anyway. However, I would already have them rewrapped if my FastTech order wasn’t sitting in Hong Kong waiting for the bomb squad! Shocked Sad

FYI, all the black and white gunk came off no problem. The gooey double-stick tape was harder, but it’s gone now too.

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After clean up.

(bottom one now taped)

tatasal
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If you are into this old/new laptop battery pack adventure like me, I strongly suggest not only a good DMM, but also a good hobby charger. It takes out the guess work. A good voltage reading out of the pack is not enough statistic, but more importantly its discharge capacity, which a hobby charger can give. In my case I keep cells that retain at least 75% of its nominal capacity for my nicer lights.

A hobby charger’s digital readout of the growing voltage rise (abnormally fast) of a cell during charging can also give you another symptom of an unhealthy cell. A cell with a still high voltage reading after a charge will collapse when subjected to a hobby charger’s adjustable discharge rate, usually manifested at 2A or higher. Oftentimes I got disappointed from cells that read good voltage readings out of a pack, only to show it ‘tiredness’ due to heat and cycles in its lifetime when subjected to hobby charger tests and readouts during after the tests.

The good new is I have not yet encountered a bad cell from a brand-new pack, regardless of its individual cell voltage when taken out of its shell. (some as low as a 1.78V pair)

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tatasal wrote:
If you are into this old/new laptop battery pack adventure like me, I strongly suggest not only a good DMM, but also a good hobby charger. It takes out the guess work.
Okay, I can’t stop calling them “smart” chargers, but I agree! But wait, there’s more!

It’s also takes out the “work” work! Just drop the batteries in and Know. Leave the dangly VOM leads and fiddly calculations in the box for “serious work”.

Recycling laptop packs gives you a slightly different ‘view’ on battery-related things. Smart chargers clarify that view.

I use the cheap-o chargers which I test as thoroughly as anything else, but I also don’t really care about capacity since I have packs of extra batteries (if I don’t pun it, who will) lying around. But I believe in knowing. If your time is worth money, smart chargers are actually revenue-positive, even if just to cull dying cells without having to carry them around…

Just trying to draw some attention to some Really Good advice…

Dim

“There is no darkness but ignorance.”

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Nominal Capacity* 2,250mAh
Nominal Standing Voltage* 3.60V
Charge Method* Constant Current-Constant Voltage
Charge Voltage* (V) 4.20 (MAX)
Charge Current* ( C ) 0.5 (MAX, above this may cause damage)
Discharge Voltage* (V) 2.75 (Below this, internal damage will be irreparable)
Discharge Current ( C ) 0.2
*
You have to remember these were not ment to be used as singular cells, they are supposed to be in a pack chargerd together, this is why the charge amps and discharge amps are low.

Simon

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tallboybass wrote:
Where could I find out how to get in those darned laptop packs without blowing stuff up? There IS a right and wrong way to do it isn’t there?
Apparently not. It’s like breaking into a wild-found honeycomb… You can tolerate a lot of waste and still come out with something sweet.

If you’re in OK, you know about ice. Specifically, Ice TRAYS. The modern plastic kind only release their bounty when you grab both ends and twist.

That twist motion works GREAT to break the welds on laptop pack shells, so you can see where to pry them open. Twist more and more welds break. The pack inside can take a surprising amount of this, but be careful. I’m not bragging a bit to say lately I don’t seem to need tools until I get to the nubs where the buss strips were welded to the batteries.

BUT… Full disclosure, I just wasted 3 batteries (awww) by grinding them together (not on purpose) until they shorted out and melted parts of the covers with smoke. I was able to solve it by dumping the pack out of the shell & pulling the ends apart. So now I only have SIX new (-ish) batteries to play with.

Sweet.

“There is no darkness but ignorance.”

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tallboybass wrote:
Wish I’d had some of those pliers…mine went ok, finally got’em out, but there was some scarring.

What does it mean when 2 of them read 4.15v and 4 of them read 4.05v??

Should I try them in a light or will it blow up?! Wink

Anything above 3 volts is usable, I’ve revived cells below 2volts, and they are happily being used daily In my own lights(single cell), as mentioned above pick up a hobby charger if you want to harvest laptop batteries, then you determine the available mAhours in each cell and then accurately group them in batches.
No need to charge them in pairs in the i4 , the charger will simply finish the lower capacity cells first.
I’m using cells with 800mAh quite nicely (originally 1600Ah and 2200mAh), toss any that don’t keep their voltage above 4 after a few weeks.

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Dimbo The Blinky wrote:
tallboybass wrote:
Where could I find out how to get in those darned laptop packs without blowing stuff up? There IS a right and wrong way to do it isn’t there?
Apparently not. It’s like breaking into a wild-found honeycomb… You can tolerate a lot of waste and still come out with something sweet.

If you’re in OK, you know about ice. Specifically, Ice TRAYS. The modern plastic kind only release their bounty when you grab both ends and twist.

That twist motion works GREAT to break the welds on laptop pack shells, so you can see where to pry them open. Twist more and more welds break. The pack inside can take a surprising amount of this, but be careful. I’m not bragging a bit to say lately I don’t seem to need tools until I get to the nubs where the buss strips were welded to the batteries.

BUT… Full disclosure, I just wasted 3 batteries (awww) by grinding them together (not on purpose) until they shorted out and melted parts of the covers with smoke. I was able to solve it by dumping the pack out of the shell & pulling the ends apart. So now I only have SIX new (-ish) batteries to play with.

Sweet.


Wow, never would have thought of that! I’ll try it on the ones coming in from ebay…thanks Mr. Blinky!!
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Not damaging a single cell in extraction can be done. I can’t remember the last time I even scratched a cell. You just need to go SLOW. This isn’t a race. You don’t get a prize if you extract the cells in 1 minute, although that would be nice.

It’s actually the opposite. The object is to NOT damage a cell. If that takes 15 minutes … Oh well, that’s the way it is.

ALWAYS pull AWAY from the cells. Never rest your pliers against the cells to use them as leverage. If all you can do is snap off quarter size pieces of the pack, well, that’s all you can do. You’ll get ‘em out eventually.

I’ve tried the twist method, but found the chance of damaging cells too great. They smash up against each other. I ++DO++ need some of those fancy pliers though.

I will use a dremel cutting disk sometimes. Some packs are kinda boxy and allow you to safely undercut, so the blade stays away from the bottom of the battery. Hard to explain.

I don’t cut the whole pack open with a dremel. Just allows me to get a hold on a corner or whatever.

Also, many times I grab a piece of plastic with needle nose and then keep turning the plers so I end up tearing off a strip like an opening key will on a sardine can. The pack plastic ends up wrapping around the pliers.

But once again, go SLOW.

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Also on the subject of removing glue, I have found that edge of a wooden chopstick works wonders. Or maybe some other small piece of wood. The wood is soft enough to not scratch the label but is hard enough to chip off the glue.

Truth is, I have no idea how the chopstick works. Sometimes I use the square edge to physically scrape off the glue. But other times, I just rub the edge briskly over the glue and it breaks up and falls off. I know this sounds like it can’t work, and you’re thinking your thumb is just as good. Trust me, it’s not. Chopstick is MUCH faster.

photon1k
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Ubehebe wrote:
Not damaging a single cell in extraction can be done. I can’t remember the last time I even scratched a cell. You just need to go SLOW. This isn’t a race. You don’t get a prize if you extract the cells in 1 minute, although that would be nice.

It’s actually the opposite. The object is to NOT damage a cell. If that takes 15 minutes … Oh well, that’s the way it is.

ALWAYS pull AWAY from the cells. Never rest your pliers against the cells to use them as leverage. If all you can do is snap off quarter size pieces of the pack, well, that’s all you can do. You’ll get ‘em out eventually.

I’ve tried the twist method, but found the chance of damaging cells too great. They smash up against each other. I ++DO++ need some of those fancy pliers though.

I will use a dremel cutting disk sometimes. Some packs are kinda boxy and allow you to safely undercut, so the blade stays away from the bottom of the battery. Hard to explain.

I don’t cut the whole pack open with a dremel. Just allows me to get a hold on a corner or whatever.

Also, many times I grab a piece of plastic with needle nose and then keep turning the plers so I end up tearing off a strip like an opening key will on a sardine can. The pack plastic ends up wrapping around the pliers.

But once again, go SLOW.


This ^^^^^
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Ubehebe wrote:
Also on the subject of removing glue, I have found that edge of a wooden chopstick works wonders. Or maybe some other small piece of wood. The wood is soft enough to not scratch the label but is hard enough to chip off the glue.

Truth is, I have no idea how the chopstick works. Sometimes I use the square edge to physically scrape off the glue. But other times, I just rub the edge briskly over the glue and it breaks up and falls off. I know this sounds like it can’t work, and you’re thinking your thumb is just as good. Trust me, it’s not. Chopstick is MUCH faster.

Chopsticks? Hmm. I think that we have a few (like HUNDREDS) around here somewhere :)…

Also, after I do the “sardine can” think to pull the tabs off (using needlenose), I just take the flat side of the needlenose, and tap the (hopefully small) pieces of the tab that are still sticking up off of the contacts. The tab metal is pretty thin, so I end up with a pretty much even contact.

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Youd’ think you’d mess up the neg poles more if you twist the spot-welded tabs, but the opposite is true. Twist in a circular motion, while pulling out. I have found that the bottom pops out more often, if you roll the tabs around your needlenose like a sardine can lid. It’s better — like I said — to pull but also twist in a circular motion.

I mean — whatever works for you — but the twist-and-pull method seems to keep neg-pole deformation to a minimum.

Also do it quickly with a wrist twist. The quicker the better. The welds will pop off, but the bottom will stay flat.

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