modified: Sunday 31 July 2016
Splitting apart lipo packs
Oh no, what idiot left me within arms reach of these things again?
Tis a shame he forgot to take them home. Tis also a shame that a few of the cells in each pack were dead. Oh well, what's the worst that could happen?
Have you read the readme page on this site yet? Of all the things on this site, this is one of the more dangerous.
Don't use this page as a major source of information on lipos and lipo safety; it is not a reliable source. Consult many other sources before undertaking any work like this, and do so at your own risk.
Although I don't intend to hurt people, I still can't guarantee any information on this page is good, true or safe. I am human, I make mistakes.
Peeling the faux carbon-fibre tape off the battery let me see the ends of the cells:
Each cell tab was soldered to wires and/or another tab. Very little isolation distance between the tabs existed: the green cardboard above was the only thing preventing shorts in many cases.
I wasn't able to desolder the tabs with the irons I had at hand (not powerful enough) so I slowly cut through them with side-cutters instead. This was a slow process, as I had to be careful not to short any cells.
Something of interest:
Can you see a small bit of drippy detritus from manufacturing? I was able to flick it off and it had not breached the cell walls.
Now came the fun part.
The cells were stuck together with double-sided tape. Last time I tried seperating cells I cut through this with a knife, which ended badly. This time I tried gently dribbling methylated spirits between the cells and slowly sawing through the tape with dental floss.
This technique worked, albeit slowly. The metho did not appear to affect the plastic cell bags over this short time period in contact. Some online sources suggested using acetone instead, but I thought that might be a bit too risky.
The final result with terminals taped up:
Now to find projects to use them! I have a few cordless drills that need power lying around...