*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?

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.

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.

Oh, and do it outside.

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

You too FM… :wink:

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??

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...

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:

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! :slight_smile:

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:

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

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

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.

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?

They look better than this now, but the wrappers got damaged a bit. :slight_smile:

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.

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.

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.

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! :open_mouth: :frowning:

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

After clean up.

(bottom one now taped)