I got the Dell Type Y4367 battery pack open. I just
folded back the 8 plastic ribs that I’d cut loose from
one side of the pack. After bending the ribs back, I
saw the 9 batteries +/- ends with metal tabs and a
long circuit board that was attached to the batteries.
I noticed that one corner of the pack had split open
part ways. That allowed me to just kinda peel the
plastic box totally away from around the batteries.
I cut the circuit board and two wires from batteries.
Took 9 Batteries with Red wraps and Blue + tops.
Wrap has no letters or #’s on the outside but some
text is slightly visible thru the red wrap covering.
The batts had been laying side by side , attached by
metal strips on the +/- sides while in battery pack.
I took a 3 pack of batteries loose from the 9 pack,
removed some tape , metal tabs and checked the
volts. Each battery of the 3 pack showed at 3.87
Volts on my multimeter. I have not done anything
with pack since then. Just trying to be slow but sure.
While cutting the batteries loose from the wires
and circuit board, a small spark popped up. I did a
little something wrong. What do you think about
this project so far ?—-Mike
Sounds like you’ve made good progress!
Those sound like Sanyo blue tops.
The spark was probably no big deal, but you should go back over things in your mind and think of how you could have avoided it. Somehow you had two things too close together.
You’re sure right about 2 things too close together.
Me and the battery pack ! 
I was using the wire
cutters when the spark happened. I was cutting the
circuit board away from the batteries , but I can’t
figure out what I hit to cause the spark.The 2 small
wires had been cut. I’ll re-figure my moves.Your pics
and posts , along with everybody , have been very
helpful to me. Keep it coming ! Thanks 
LOL! Good caveat!
I did say “VERY” lucky… And I’m glad you noticed the subtle ironicality of “gently crush”…
To me, seeing the seams makes it seem easy. That’s all “gently crush” is for. Put the pliers right at the end, find the seam, slip in a wide screwdriver or wood chisel & twist. Thinking about it, I’m not sure I leave tooth marks on the plastic with the pliers…
To be perfectly frank, I’m lucky to have enough strength in my hands and forearms that I can USUALLY simply twist most non-Dell packs enough to fail “enough” of the plastic-welds that I can grab a corner or edge with the Channel-Loks & just peel the plastic off. Yes, I get pinched a lot when I forget to wear gloves. And yes, it’s a dance between brute force and subtle finesse, but as Elwood said, “Whaddya want fer nothin?”
This is why I prefer Dell packs over all others (so far). Peel the sticker, rip out the rib, break the “bucket” back & the batteries pretty-much dump right out. When I try it, anyway… Plus Dell is far enough up the battery “food chain” that they load the best 18650s (year-for-year — later means better, of course) in their packs.
The steel buss strip is what causes the circuit through the 18650s. Once you start removing it, there is progressively less chance for that spark. But that strip is welded on to the ends, so until you break it loose, it’s = to whatever end(s) it’s attached to. E.g. in your 3S string you mentioned, that buss strip would give you 11.61V until you broke it loose!
The worst spark I ever made was trying to pry that strip off a ‘+’ end when I mashed through the plastic wrapper on the shoulder. It was still connected to make a 2 or 3S string! THAT was exciting!! Unfortunately for me, my Flush Cutters don’t really help, and they’re expensive to replace, which is why I roll the strip off with needle nosed pliers. I get to clean the nubs off regardless, so I just try to expedite the process of freeing the 18650s.
Remember, I said that I’m not mechanically inclined.
I also need help understanding some of the directions.
I have an idea what you mean when you speak about
a 2 or 3S strings. How to tell which one is 2 or 3S ?
If you look at a pack-full of batteries as they first pop out, you’ll notice by following the stainless steel buss strip, there are (e.g.) 3 end-to-end and 2 abreast. That’s 3S, 2P or 3 in Series, by 2 Parallel.
Total Voltage of the string is multiplied by the number of cells in Series, available Current is multiplied by the number in Parallel.
When I read this posting, I realize that I’m not as
smart as I thought ! I can’t understand what you’re
trying to tell me. Here’s what I saw when I opened
the Dell Y4367 battery pack. I saw 9 batteries laying
side by side in a 6.5 inch row on a tray.The 9 batts
were laying in this order : + - - - + ,if viewed
from one end of the batts. On this end of the batts,
there’s a 6.5 inch thin metal tab soldered ,with tape,
ONTO all 9 batteries. Looking from the other end of
the batteries , the view is in reverse: - - - + - - - .
This end the batteries didn’t have a continuous piece
of metal across the 9 like the other side .This side, if
I remember, had a metal tab soldered to 6 batteries
like + - - - and the other 3 batts had a tab to - - - ,
with the end to the circuit board. If I am correct ,tell
me what you think. What’s the meaning of ” in series”
“and in parallel” Remember, I’m not mechanically
inclined.
Thanks for the link
I spark is usually when you have pried against the heatshrink whilke trying to rip the tabs off the top of a battery .look for a tiny hole in the heatshrink .
cut wires loose and when all the batteries are free just rip them apart hang onto batteries and pull them from the pack . You'll only see sparks if you have a metal tool in your hand and are cutting .. I remember when i was a noob i used to disassemble them really fast and acted like it was a bomb because i had no idea what i was doing .. now i realize it's a bit simpler than all that get the pack out of the plastic and just rip the batteries apart .. then clean the tops and bottoms carefully so you don't touch the tip of the tops and something under the heatshrink // side of the abttery with pliers etc ..
*TIP -Don't over clean them since you may find they are worthless crap and have wasted time getting them all super cleaned up .. just get the big stuff off em and charge them and then test them . If they are good then spend the time cleaning them up .
use the search on BLF and just type in lap top pulls or laptop pack etc and you'll find 3 days worth of reading on the subject .
good luck 3,75Volts sounds promising but I just tossed a bunch of royobi drill pack batteries which looked good at first too .
One sure way to know if a battery is junk is if it won't hold it's charge .. if you charge it to 4.2 and wake up tommarrow and they are 4.15 and next week are 4,.11 after just sitting on the shelf guess what .. crappola recycle them
First, it’s been awhile since I did this, and I don’t think I’ve opened that particular pack, but they all work essentially the same.
That steel strip is the equivalent of the buss bar in your household breaker box. It’s flat so it fits, yet wide so it gives enough cross-section to carry as much current as possible. It’s stainless steel so it can be spot-welded to the ends of the 18650s. It’s easier to see how it’s connected as you rip the 18650s from its clutches.
You see how it runs from + to + or - to - on some sets, and from + to - on others. When it goes from + to , that creates a Series string (aka “pack”, if you’re building them) of 18650s. Two connected + to is abbreviated as 2S. Add a 3rd and it becomes a 3S string. When that buss strip joins + to + or - to -, it creates a Parallel arrangement, abbreviated as 2P or 3P. Laptop packs I can recall never got to 3P, but when the pack builder needs more depth (i.e. deeper discharge capacity), that’s how they get it. I suspect your pack is 3S/3P, since you have 9 18650s…
If the 18650s have, say, a 2200mAH capacity, 2P would give you 4400mAH. Since the “nominal voltage”, IIRC, is 3.9, 3S would give you 11.7V. You can now look at the label for the V and mAH ratings of the pack & tell how the cells inside are arranged, as well as the nominal capacity of the individual 18650s.
Tapping into the center of the physical string isn’t electrically relevant, except it keeps the current path through the buss strip short and balanced. And gets the + tap closer to where the laptop likely needs it.
Hope this helps…
Boaz; I’m being real slow with the batteries. I took
just 2 batteries of the 9 that were in the pack and
charged the 2. It took a very long time to get the 2
up to 4.18—4.19 volts-It was 4—4.5 hours charging.
Each battery test started at 3.87 volts. This charge
cycle was yesterday. I just checked them and both
were 4.17v. The 9 batteries that are in the pack had
Red wraps and a blue + top on them, but NO markings
on the outside. You could look thru the wraps and see
some markings on the batteries. On 3 of the batteries
the markings were JIUFK17 and J43A . Also, besides
those 2 markings, each of the 3 batteries had 1 set
of six digit #’s.—019329 or 141502 or 019326.
I took this info off the 3 batteries only. I haven’t
looked at the other 6 batteries for markings.
DimboTB, What do you do for a living ? Are you in
the electrical business ? You said ” I hope this help’s”
Yeah, I’m still confused. Whatever type of work you
do, it’s not your fault that I’m just not mechanically
inclined. But keep throwing info my way, maybe I’ll
catch on.
I have pulled a bunch of different packs and they are all different to get into. Generally speaking I just look for a seam and get it to crack open. Rip off stickers and see what is under them. Whatever it takes to get started. After that it’s brute force. Ripping the top or the bottom off. After that I yank the batteries completely out and free of the circuit board and just start ripping batteries off of each other. I’ll use needle nose pliers most of the time for that and gloves are a necessity. These lenovo packs that I’m ripping apart right now are a bit of a PITA and I’ve had lot’s of sparks and burnt marks. Well not LOT’S but more than usual. I’m only keeping anything that is 4.0 or better. However, if you buy brand new packs they are often really low because they have never been fully charged in the first place, but that is a different story.
Not that I really suggest my brute force measures but for me working faster just seems to be a better idea. The way I do the, if I do short them it’s only going to be for a second anyway. Ripping and tearing while keeping the wires away from each other while moving fast works for me, might not work for everyone though.
18sixfifty: In regards to the using of “Brute Force” to
gain entrance into laptop battery packs.I’d place that
in the “By any means necessary” category. 
LOL well not ANY means but I’m sure I’m a little rougher on them than a lot of people would be comfortable with. Once I can get my fingers in a seam I just rip them apart. A lot of times the plastic is all ripped up when I’m done. Other packs come apart easy though. But pretty much I would rather use my hands than any tools if possible. A set of pliers to get a seam to crack works but after that I just tear them apart, piece by piece if I have to.
YMMV when it comes to the difficulty of opening packs, some are like opening box of chocolates, while others it could be like blowing a safe open with TNT.
You do what it takes, in order to get the job done.
Nothing is wrong with that outlook.
I understand what you are showing—-point taken !
Sorry, man. But one of my “character flaws” is I never give up.
No brag, but the “pinnacle” half-decade of my career actually was a job building & servicing industrial robots. Built hardware & computer interfaces, wrote device drivers to let the User drive my hardware through the application written by a co-worker, solved problems & fixed things.
Then I moved on to telephone technical support. I’m usually pretty successful at explaining difficult technical subjects.
To brag a little, the past few days I’ve been working (successfully) to get a Jumbotron TV beside the pool at a local dormitory up and running. The City won’t let them show the Big Game up there because the electricians haven’t finished the “safety lighting” whatever THAT is around the pool deck.
But enough about me.
This seems to have helped:
So …
If you’ll look at the “box of chocolates”…
Notice how the pack is made up of 9 18650 batteries? Notice how there are 3 “rows”, each made up of 3 batteries in a row? The 3-in-a-row parts are the Series connected batteries, connected + to . That is referred to as “3S”. The 3 rows is the Parallel part, connected + to + and to -, which is expressed (in this particular example) as 3P.
So the “box of chocolates” is a 3S/3P pack, meaning if the individual 18650 batteries have a capacity of 1500mAH (meaning they can deliver 1500mA, or 1.5A, for an hour), the 3P part would mean the pack would be capable of (1500*3) = 4500mAH. Not to belabor the math, but this can also be expressed as 1A for 4.5Hours…
The 3S configuration, at a nominal voltage of 3.9v, means the voltage at the output terminals of the pack (where it connects to the charge-controller circuit board) should be 11.7v (obviously varying as the charge is depleted or replenished in use and recharging). If I could see the numbers on the labels, I’d work the formula backwards for you, so you could know from the label what to expect from each 18650…
That’s just electricity and math. Mechanically, you’ll notice all the batteries lie the same way. The + ends can be identified by the crimped collar at that end. This means the pack is tapped at the ends — a perfectly acceptable way to do it, especially with so few batteries. If you find a pack (normally with an even number of batteries) where the - ends of the batteries are all at the outside ends of the pack, and the + ends meet in the middle, that would be a “center-tapped” pack, which you may find someday, somewhere…
That’s about all I got. All that’s left is to remind you there are no dumb or bad questions, only dumb or bad answers.
Thanks for reading.
Dim
EDIT: Not to be redundant, but to put an example out, in hopes of making this seem as simple as it really is (and since Mike asked in a PM but it seems useful):
It’s just straight Math, and the only formula you’ll need is Power, which is P=IE or “Power (in Watts) is equal to the product of Current (expressed as “I”) and Voltage (expressed as “E”). Yes, that’s an arcane way of identifying Voltage (“Electromotive force”) but it makes the mnemonic into “PIE”, as in “Easy-as”…
For example, your ‘B’ pack: “B-Dell_Type 3R305-11.1v-4320mAh-Capacity48WH” — here goes:
P (48WH) = I * E (11.1v)
So to isolate I, or Current, using simple Math rules divide both sides by 11.1.
48/11.1=4.324A or 4324mA, which is close to the mAH number given so you can check your Math.
Then you have to realize that 1000mAH from an 18650 isn’t worth the bother, 2000mAH is a lot, and 3000mAH is a fantasy. So your reality check is,
4320/3 = 1440 (unlikely)
or
4320/2 = 2160 (likely)
Your B pack has a 3S/2P configuration of six 2160mAH cells.
So when we get one that isn’t fully labeled, like your:
“A-Dell_Type PC764-11.1v—Capacity56WH”
P=IE
56 = I * 11.1
56/11.1 = 5045
5045/2 = 2522.5mAH per battery, which would make that A pack very interesting, even with only 6 18650s (3S/2P) inside.
Hope this helps.