On Tue, 24 Aug 2010 10:53:14 +0100, john hamilton wrote:
I'm replacing a small button battery (CR 2032) with two AAA batteries, I'm
intending to leave the old discharged button battery in its place and solder
the leads from the AAA batteries directly on to the button battery.

Is the heat that I would need to apply to the button battery with the
soldering iron to solder to it, likely to make the battery prone to
'leakage' in the future? Or perhaps cause it to go bang at the time of
soldering? Thanks for advice.

I've soldered to batteries many times.
Heat a spot on the battery, leaeve a blob of solder.
Tin the wire with solder.
Reheat blob on battery, stick wire in blob, remove iron, hold very
still while it cools.