[Duo2400] Disassembling seemingly welded cells

[Ben Smith]

> -----Original Message-----
> From: Duo/2400 List [mailto:DuoList at lists.themacintoshguy.com]On Behalf
> Of Robert R. Daniel
> Sent: Tuesday, February 25, 2003 5:23 PM
> To: Duo/2400 List
> Subject: [Duo2400] Disassembling seemingly welded cells
>
>
> All the recent talk of duo batteries has gotten me motivated
> to rebuild a couple of mine.  But I have run into a problem.
> The 4/5 non-tabbed cells in the three type III batteries I have
> cracked open (and tried to take apart) seem to be welded
> rather than merely soldered.
>
> Or at any rate, if they are, it is a solder that will not melt or
> soften under my soldering iron.  I have actually torn the metal
> strip which conducts the electricity between cells when I tried
> to force it to separate from a cell.  And on closer inspection,
> the point at which it is attached looks more like a minute
> arc-welded joint than a soldered joint.
>
> How in the heck does one separate and remove the cells?
>
> Thanks in advance.
>
> Robert

As you observed, the cells are indeed spot welded together, NEVER try to
solder directly to a cell, the heat will damage it, also do not replace
individual cells in a battery pack, the capacity of new cells will be
different from the old ones and they will charge unevenly, this will lead to
the pack failing sooner than expected, (you can however sometimes use the
best cells from 2 old packs to build 1 good one).
if you can, it is best to have the cells professionally welded (spot welding
is used as it produces very little heat, and what it does produce is highly
localised).
otherwise, always use tabbed cells and try not to use too much heat.
Ben.