Saturday, January 26, 2013

Busting open a Laptop Battery Pack

There are lots of posts about people doing the hackgeneer thing - taking things apart- this is mine.

Walking past the recycle bin at work I spied a laptop battery pack. Needing rechargeable cells for various outside Arduino projects I filched it.  After all, it is a recycle bin - and I am going to recycle it...

pack with its top off.

I always wanted to know what was in one of these.  Suffice it to say - it was quite satisfying getting at the innards of the pack - involving ripping, cutting, and general plastic destructing mayhem.  I was cognizant that shorting unprotected LIon cells can be exciting - So  I did this on a non flammable base (Correll dinner plate - don't tell the wife - please)
View of all the pieces
view of pack and its controller board.
What I discovered is a 6 cell pack with 3 sets of parallel batteries in series - Marked with SE US18650.  I had suspected that the pack contained 185650 cells- should give about 10 volts fully charged.
 I was astonished how big these things are.  I expected them to be a little bigger than an AA battery, but these things are HUGE in comparison..

I tested the voltage of the 3 packs - and they had relatively normal voltages on them. I suspect that their capacity has been reduced to the point that they won't run a Laptop for long enough - but should be stellar for supplying a few dozen milliamps to an Arduino - for quite a long time.

I just have to track down some protection boards to keep them safely contained.  Seems that everyone has them for a couple of dollars or so.

Now that I have a few - i am looking around the net for how to use then.
See here
gota see this xkcd:
NOTE: in the interest of safety - Mistreating Li-Po batteries are Dangerous 

Stay tuned ...