Depends how old your pack is. Mine was from my laptop and it was over 5 years old. The plastic hardens and got very hard and fragile. No way to open it or pry anything open, it was all heat melted together and sealed.
Tear off the battery label on top or where ever you can find some place or holes.
Cut along the top with a dremel to remove the lid or anything that holds the battery, in a way that minimizes you to cut into the batteries. They are usually glued in with something, maybe permanently, maybe temporarily, it may be better idea to cut the bottom off and take it with the batteries out, then pry the batteries off the bottom.
I wanted to keep my enclosure so I cut the top open.
A little bit of heat on the seams with a heat gun or hairdryer helps to keep your cells pristine. Tearing it apart piece by piece (like I did my first one) can result in nicks/dents in the cells. I ended up throwing away 2 cells iirc because of tiny indentations that probably wouldn’t hurt anything but at $1 each ‘better safe than sorry’; ended up re-wrapping the other 10 after sanding/filing the little metal barbs left on the poles of the cells.
To get the batteries apart once the pack is disassembled just grab the metal connector near the pole with pliers and pull/twist. Should leave 4 small little barbs/nubs on the poles of the battery.
There’s no one way to open the various packs. Twist, pry, cut, and peel the plastic case apart. I can often hold or wedge a small gap with a ‘popsicle stick’ and then work along a seam with a flat-tip screwdriver. Sometimes a seam will be ultrasonically welded and require peeling or ripping apart. Always avoid poking or shorting the batteries. They will be interconnected in groups with thin metal strips or tabs. Clip any wires soldered to the tabs, and lift out the grouped cells.
Again, always avoid poking or shorting the batteries.
Here’s my advice for dealing with the tabs:
Don’t - It’s tempting to peel the tabs off the battery terminals. This leaves about four very sharp spot-weld nibs to be removed. Sanding or grinding them off with a Dremel or whatnot scratches through the protective finish, and scatters particles which can enter the vent holes. I know someone who continues to peel and Dremel with a grindstone. After a few months, his scratch marks show what looks like rust.
Do - With small side-cutters, clip the tabs close to the terminals, remove sharp corners with fingernail clippers, and gently burnish or rub the edges down with some rounded, chromed tool. The tab metal is malleable, and can smooth down quickly. Overall, this is simpler, and leaves the batteries slightly longer for better pressure against flashlight contact springs. The side-cutters I use are Plato® model 170, and Xcelite® model 170M. I recommend wearing glasses or goggles - if a sharp, hard-steel tip of these tools breaks off, it could instantly enter your eye.
Ensure proper insulation - Ideally, your batteries will have intact shrink-tube covering the entire length, and extending somewhat around the ends. Sometimes, a salvaged battery will have shrink-tube cut too short, or split somewhere. Flaws can be repaired with clear postal tape, or a glob of PVC cement, or a new piece of thinwall shrink-tube. FastTech sells suitable shrink-tube in several colors, like SKU 1323904.
Opening the battery pack? Simple. A steady (really steady) hand and a Dremel Tool works every time.
Clip the tabs connecting the batteries to separate them. Don’t bother removing the tabs yet. If you don’t have a hobby charger, find someone that does have one. TEST each battery (load/drain/charge and check capacity) BEFORE you waste any time or hope on the ‘unknown’. Hint: any 18650 size battery that has a less than 1000mah tested/confirmed capacity or does not charge up properly, is a dud. Batteries that fail the test can be disposed of.
The ones that meet spec are worthy of a little more time to clean them up, whether it’s fixing issues with the wrapper or removing the tabs. Some tabs are soldered on at the factory. Some are welded. Makes sense to use a good soldering iron to remove the soldered ones, doesn’t it? If your iron is a high wattage type the tabs will come right off without having to leave the iron on the battery to long and damaging it by overheating it. I have done a bunch of these and never had any problems at all. For the welded tabs, see two¢¢’s post. His method works well for that.
Note: clip one wire at a time. These half-charged batteries can produce a surprisingly powerful arc if you try to cut 2 simultaneously.
Generally there are no cells close along the seam where the contacts are. It's safest to open this seam first. I like large tongue and groove pliers. Sometimes pressure will pop the seam, sometimes you have to grab and twist to pop it, then walk your way down the whole length. The cells are usually close against the opposite curved side so I usually leave that side like a hinge when I can pull the pack open. Don't be tempted to slip something inside and pry against the cells. The plastic is stronger than the cell walls.
Sorry, credit goes to DBCstm for that tip. I’ve only done a few packs (some very easy and some very difficult releasing some magic smoke ). It seems to me that one area to start prying up on the seam to pop it apart is nearest the power connectors (where it makes contact to power the laptop) and then hinge it up and over the other side (as Gj says). And also as Gj said, be sure to only cut one wire at a time! Easy mistake to make. Don’t get in too much of a rush; take your time.
As far as testing cells afterwards: There is a voltage limit where you keep cells above and toss cells below (voltage as-is out of the pack). I think that limit is about 2.5v??? Then you charge up the pulled cells, measure voltage off the charger, measure again 24 hours later, and then I measure 1 week later to make sure they are not self-discharging. I think someone told me that up to 0.10v is acceptable for used laptop pulls (???). Personally, all of my pulls have only dropped about 0.01v to 0.02v over the course of a week. (If you have a hobby charger, skip the following.) My next step is then to put them into a flashlight with a direct drive driver and compare tailcap current on high with a known good cell. Lastly, a runtime test in a light where you expect a certain runtime (i.e. a light with an XM-L and a Nanjg 2.8A driver should yield around 45mins or a little more if your cells are expected to be 2600mAh) - check tailcap current over that runtime though because you may find the light last for 58 mins but only pulls 1.5A or so (like my recent LG pulls).
I use pliers and brute force to open the packs. Use caution with any metals tools to prevent shorting the cells. I like to keep a metal trash can handy and have an emergency plan in case something goes wrong and I do short something out badly. Count on keeping some of the shrink tubing from FastTech handy as it makes your cells look much more professional, and I invariably end up tearing the wrap on the factory cells. The Fast Tech wrap is extremely easy to apply only needing a hair dryer. I always mark my pulls with a Sharpie to indicate the date pulled, use of the cells, and any other needed info, e.g., I write "King" on four of them for use in my King, so I can keep them as a matched set when I charge them. I also like to have multiple colors of wrap so I can track pulls by overwrap color.
After reading this thread I remembered I have a lipo pack my mother in law purchased for her old laptop. She decided a month later to get a new laptop instead and gave me the battery pack. Until now I had no idea what to do with it. After some digging Ive found it. It says, Japanese cells on the box. 10.8v, 4800mAh, 50Wh.
Any ideas whats likely to be inside based on the numbers?
**Note to others, the chisel works easy. Took me maybe 4 mins, Ive never done one before. Just pop it under the seam, maybe 1/2 mm, just gripping the edge and twist the chisel. Move along the seam, repeat. It soon pops right open like an oyster, and you find your pearls within.
Thanks Garry, yeah its 6 cells. Doesnt say on the pack that I can see. But I did see them.
CGR18650CG x 6
I assume, the two red wires I pulled from the sies of the batteries did not penetrate the battery and instead are temp probes maybe that sat on the sides in the white paste (heatpaste)?
And I assume these are welded, not soldered by the looks of the spots.
If I put a layer of say blu tack over the vents, then lightly sand/file off the nubs, will that be a bads thing. Obviosuly I would not want blu tack to go inside, nor would I leave it there.
The laptop was I think a Toshiba. Older, not even dual core. Ive had the pack for maybe 2yrs now. She bought it as the old one was not holding charge, but then decided she was due a new laptop anyway (got herself an i5) so the pack never saw any service, at least not much, maybe a month.
The replacement pack is a ‘2 power’ brand going off the cardboard box it came in.
Are they safe tech? I assume they are no longer protected.
Edit: and they test at 2@1.6v, 2@1.8Xv and 2@1.9Xv. Interesting how they appear to be in pairs.
This was the mistake I was making. I was doing quick, deliberate cuts but still once and a while getting a spark when I made the cut. After that I started paying attention to how they were wired together
