Is this lithium ion battery bad and/or dead?

[corrado33]

Hey guys, I was going to go to a battery forum, but well no one ever answers on those forums.  Anyway, if any of you have had experience with lithium ion batteries, I'd appreciate if you could answer me this question.  Looking at these two pictures,you can see three separate battery packs, which, in turn are made up of two different li-ion batteries.  In case you are wondering... yes this is an old MBP battery.  So, you can see that one of these packs has kinda... exploded.  The silver "lining" isn't tight against the battery anymore.  This battery has stopped working, and I was wondering that if I bought new li-ion batteries to replace this one (or all three most likely), if it'd work again.  Do you think that this is possible?  Also, do you think the one "exploded" battery is causing the whole battery pack to not work?

Thanks!

EDIT:  It's be useful if I attached the pics...

[z.s.tar.gz]

If you replace the batteries, then of course it will work! And yes an exploded one will certainly ruin it for all of them, especially if they're in series.

You may be able to replace only the exploded one if that's the only thing that's exploded.

[madsci1016]

I have repaired batteries in similar situations. Measure the voltage across every cell to determine if that cell is good or not. Then replace the bad cells.

[corrado33]

Awesome!!  However, I'm not quite sure how they're wired, although I'm sure I can figure it out with a few multimeter probes.  Also, the entire battery is rated at 10.8 V.  From the looks of those batteries, does it look like 3 11V cells in parallel, or 3 3.somethin cells wired in series?  (I think I got that right... it's christmas break... my brain is turned off...)

[z.s.tar.gz]

There's really no way to tell from the pictures as that all depends on the wiring.
Judging from the size of them though, I'd put my 50-50 bet on parallel.

[SmAsH]

Does it give a capacity? I'm thinking if they are single cells they are in series because one cell is 3v7, 3x3.7=11.1

[z.s.tar.gz]

why not measure one with a multimeter?

[corrado33]

It says 60 Wh, at 10.8 V so 5.5 ah or 5555mah. 

And yes, I'm being lazy and wanted to get other people's opinions before I got the multimeter out... 

Hmmm... anyone ever wanted to see the inside of a MBP battery?  I finally got it all of the way apart, and found some nice serial numbers on the bottom of the battery.  Turns out it's 3 3.7v cells.  They are VERY similar to this battery...

http://worcell.com/product_info.php?products_id=74356

And in fact look exactly the same.  Here's the serial if any of you want to find the exact specs for me...

Sony Fukushima Sew US604496 K3   Then some other random numbers are below that are... 0HC91OE29F  (I didn't get any hits on the search for that number)

ACTUALLY... it LOOKS like it's 6 1.85V cells as there are two different sets of "wires" coming from each "cell", and each "cell" consists of two other smaller "cells" taped together. 

It turns out that only ONE of my SIX cells are bad(from the looks of it)... although I don't think you can buy the individual 1.85v "cells".  I'll probably end up buying three new 3.7v cells as mixing old with new is not always good.  But I AM getting a nice new battery charger for christmas, so maybe I'll find a use for the old ones? (And yes, it has Li ion capabilities such as balancing etc...)

[z.s.tar.gz]

Blind opinions instead of numbers!? Say it ain't so!

[corrado33]

Yeah yeah yeah I know I don't REALLY know what I'm talking about, but I'm trying. 

While doing further research on the batteries that LOOK like my batteries... i've come to the conclusion that this battery PROBABLY is 6 cells.  However, there are two batteries in each of three groups.  These two batteries are wired in parallel.  (Hooked up through the same metal prongs, and batteries are facing the same way. 

Anyway, I'll do some more stuff in the morning.  I can't get the multimeter yet as I can't go into the garage cause our lovely dogs are out there, and they'll bark if I go out then come back in. 

We'll see how this thing comes together in the morning...

[SmAsH]

Are you sure? I thought li-on's only came in 3.7v cells? Are you sure they aren't 2+2+2 wired in series parallel?
But yes, the multimeter will confirm.

[corrado33]

Are you sure? I thought li-on's only came in 3.7v cells? Are you sure they aren't 2+2+2 wired in series parallel?
But yes, the multimeter will confirm.

That's what I said in my most recent post.  But I forgot my multimeter is at school, and i'm going down there today, so we'll see what it is a bit later.

[Daanii]

It depends on the lithium-ion chemistry. Some cells are almost 4 volts. Some about half that.

[corrado33]

So, I finally got my multimeter.  The voltage across 2 of the six cells, wired in parallel, is 3.7v.  So it looks like they do have the 2x2x2 config.  There are three sets of two batteries.  The three sets are wired in series. 

Also, that fifth cell that I thought was good... Turns out it's not. The broken cell broke the other one.  So I have 2 sets of 2, which is cool cause my charger can only handle 5 cells anyway. 

So, since they are wired this way... does that mean the individual cell specs are
(For each of six cells)

Voltage: 3.7
mah: 2777...

I would say this because the two batteries in parallel would double the capacity, taking it to the 5555 mah mentioned earlier.  Then the three sets wired together would bring the voltage up to 10.8 (well 11.1 but whatever), but not do anything with the capacity.  Correct?

[z.s.tar.gz]

Series regards voltage, parallel regards current.

[SmAsH]

Each cell *should* have half the total mAH.

[corrado33]

Hmmm... so I figured I'd try somethin cool, and just use THREE of the good batteries to try to make a useable battery that simply had half the life of the old one.  I wired and soldered everything up... probed everything with the meter... and... NOTHING.  It's weird, because the little battery indicator on the bottom of the battery works... (you push a button and it lights up leds to tell you how much battery life you have left.), but the computer won't recognize it.  Also, I don't know if there is supposed to be a voltage at any of the pins when the battery is just sitting there, but there isn't.  And I have no other way to test it.  Any ideas?

[SmAsH]

Were they charged to begin with? Have you tested the cells individually?

[corrado33]

Were they charged to begin with? Have you tested the cells individually?

Ha heck no they weren't charged to begin with.  This battery has been sitting for a while... I was just seeing if I could revive an old paperweight.  Each of the cells do test for 3.7v, and across all three it tests 10.7.  I think it has something to do with the electronics in the mini PCB, as I'm not getting any power to the pins.  I'm guessing that when the one cell blew, it fried something in the pcb...

UPDATE!!!:  It seems I forgot that when I took this apart... i accidently ripped this thing off.  Anybody know what it is?  Soldering iron is away for the night so I'll have to wait till tomorrow to actually solder it on there.  It looks like a tiny black blob with two wires coming out of it.  Don't mind the white stuff... it's...umm.... glue.... yeah that's right... glue...  Actually it is glue apple used to secure it in place lol.

UPDATE... AGAIN!!:  Seems to have a resistance of 150kOHMs. Maybe a simple resistor?  PS... got my battery charger today.  I got a good look at it before it was stolen to get wrapped for christmas...  I'm excited :-)... well, excited to use my homemade PSU lab bench supply to power my expensive charger to charge my probably dead LiPo batteries... :-)

Here are the pics...

[Soeren]

Hi,

It's probably an NTC resistor or similar kind of temperature sensor.
Try heating it by holding it between your fingers (or a lighter in a safe distance for not ruining it) and measure it while heating it - if the resistance goes down radically when heated, it's an NTC resistor.

Perhaps the failure to get it going is the battery governor, that needs to be reset, as this is a security feature to avoid the possible charge on a battery gone bad (to keep you and your surroundings safe).

[corrado33]

Hi,

It's probably an NTC resistor or similar kind of temperature sensor.
Try heating it by holding it between your fingers (or a lighter in a safe distance for not ruining it) and measure it while heating it - if the resistance goes down radically when heated, it's an NTC resistor.

Perhaps the failure to get it going is the battery governor, that needs to be reset, as this is a security feature to avoid the possible charge on a battery gone bad (to keep you and your surroundings safe).

Turns out it IS an NTC or temp sensor of some kind.  The resistance dropped to 90ish when I held it between my fingers. 

So... exactly how would one go resetting the battery governor?

[Soeren]

Hi,

For that, you have to try Google with the battery model number and perhaps "lithium reset circuit" will help.
Even better might be if you have the IC type numbers for the security circuit to search for with "reset" included in the search string.
If you can find the datasheet, post a link to it if you cannot see anything from the sheet yourself.