Replacing watch batteries as others have said is pretty easy, 90% of
the time. Taking the back off is usually pretty easy, unless it is
screw-on style, requiring a special wrench and vise. Getting it back
on is where the trick usually is, and is where the damage is usually
done. If it’s hard to get off, it’ll be harder to get back on.
Pressing the back with the watch on a flat surface is usually OK as
long as the crystal is flat and the table or bench surface is flat,
if it’s not flat, you will break the crystal. Press on the edges of
the back- not in the middle or it may bow out and make it that much
harder to snap in. Use of a back press is highly recommended for all
press-fit watch backs when possible. The money you will save doing
20 watch batteries yourself may allow you to buy a press, so that
might be an option. You can get individual batteries at Radio Shack
or Wal-Mart, or order them from any of the regular jewelry supply
houses, but you may have to buy multiples from a wholesale source.
For the savings of 20 batteries installed by a shop you might be
able to get an entire watch battery kit and be able to change them
for others at a profit. Most jewelry supply houses carry the kits.
The reason they cost 9 or 10 dollars is because of the tools
required, and to insure against the infrequent broken watch. There is
good money in changing watch batteries - until you break one (watch
out for Casio, Fossil and Gucci watches! Nothing but trouble, those
three. Some watches have a reset circuit you have to short out with a
pin or something too, an instruction note will be on the inside of
the back). Like Kelley, I offer a bulk discount, and would recommend
you find someone in your area that does as well, if you don’t want to
get a press and learn how to do it and don’t really care if you mess
one or more up. It’s best to learn on your own watches, sounds like
you have the perfect opportunity.
If you are planning on selling the watches with the new bracelets
you are making, adding in "The next battery for free with purchase"
or “Lifetime Battery” or something like that might be a great
marketing tool, and would only cost you pennies.
Once you get the batteries changed, pull the stems out while the
watches are not in use. That shuts the watch off and preserves the