d0c - 8-8-2006 at 12:18
I would be very happy if someone could give me a short but secure instruction on how securely open a car battery without causing any electric shocks,
circuits, explosions or anything similar to that.
I need to extract the membranes and the lead AS ONE.
thanks a lot!
evil_lurker - 8-8-2006 at 12:37
Good freaking luck. Those things are made of near indestructable plastic.
My advice would be to start by draining the electrolyte, then open up the battery with a chainsaw.
Vitus_Verdegast - 8-8-2006 at 12:50
I already gave details in the nitroalkene reduction thread in technochemistry!!
drain electrolyte, wash a couple of times w water, heat the plastic with a heat gun until it softens and **carefully** cut the plastic using a sharp
knife.
UTFSE!
d0c - 8-8-2006 at 15:23
let's say I wash the inside with dH2O, while opening it, is it not possible to cause exothermic reaction , electricity flow or anything like that,
that could be harmful?
Once opened a Alkaline Cell and is was VERY exothermic, when the membrane was hurt.
Vitus: What do you understand by "carefully", what could happen? What should not happen exactly?
Vitus_Verdegast - 8-8-2006 at 15:31
if the electrolyte is removed (dil. H2SO4 here in the car battery) no exothermic reaction/shortcut can happen?? The battery will be empty before you
attempt to cut it!
By carefully I mean:
- don't cut to fast and to deep as to not damage the separators inside
- don't hurry and slip, resulting in cutting yourself and thus possibly resulting in hospitalisation
take your time, heat until soft, cut, heat again, cut etc...
[Edited on 8-8-2006 by Vitus_Verdegast]
not_important - 8-8-2006 at 16:49
To slightly expand upon Vitus_Verdegast 's method : empty acid out, keep for whatever. Fill with ordinary water, rock the battery a bit, let sit for
a few minutes, empty; repeat several times. You want to let it sit so as to give any acid a chance to diffuse out of nooks and crannies. This removes
all the fun and excitment of spilling sulfuric acid on yourself.
unionised - 9-8-2006 at 10:08
If you make sure the battery is flat first you have less acid to wory about.
Rosco Bodine - 9-8-2006 at 11:34
If it was me doing this job , I would just set the blade depth shallow like about 3/8" on a circular saw
" Skil Saw " , and after draining and rinsing out the battery lay the battery on its side and make lengthwise
cuts just below the top of the lid , along the sides and the ends , turning the battery after each cut
until it is decapitated . If the terminals are molded into the plastic , heat 'em up with a torch until the plastic is melting and lift the assembly
, pulling the terminals through the softened hot goo . That ought to work nicely .
An old butcher knife heated really hot in a torch flame
could also be used to make melt cuts the same way
in the case , but this would probably go slower than using a saw . The edge of a horizontal disc grinder
could also probably be used , perhaps with a small
circular saw blade on the arbor if the grinding disk
was grabbing in the plastic instead of cutting .
Slower going would be a small cutoff wheel in a dremel
tool , or faster if used as a side slitter chucked in a laminate trimmer type router . I think I have also seen a plastic cutting heated blade
attachment for torches , and also for large soldering irons , but it is not a common accessory item and would be difficult to find .
Hey , where there is a will ....there is a way 
leu - 9-8-2006 at 16:55
Heating the plastic to soften it and using a sharp cutting instrument is more likely to preserve the contents in one piece than using a power tool
Using a cutting wheel on a battery is rather dangerous, sometimes this can
ignite the battery 
This technical manual for a brand of lead acid battery should
give you a lot better idea as to the type of construction that you're dealing with:
[Edited on 10-8-2006 by leu]
Attachment: techman.pdf (161kB)
This file has been downloaded 692 times
Rosco Bodine - 9-8-2006 at 22:50
An autopsy saw would be just perfect , just like separating the skull to get at the contents
Stick an oyster knife in the crack and twist to
crack it open , like breaking open a clam ....
nothing to it
saltykid - 16-8-2006 at 13:16
I'm curious as to your reason for wanting the membrane & lead intact, sounds like you have an interesting project planned
Definately drain the acid first, that is your main problem when dissecting batteries. Here's something to consider trying as far as actually
getting it apart safely.
After all of the acid is drained... use a soldering instrument... against the plastic. Slowly press down on it and drag it in a straight line where
you want to make a cut through the plastic. Slow and steady is the key.
It will melt most of the way through the plastic, allowing you to seperate the rest easily with a sharp knife.
EDIT: P.S. when I have done this I used a metal-sheathed "utility knife" to do the final cuts. This seems to be the safest way to cut that sort of
plastic without risking nasty cuts to ones' hands in my experience.
[Edited on 16-8-2006 by saltykid]