I am confused.

I would like to get some watch batteries. I have about six watches, and four of them need new batteries. There used to be a very helpful gentleman in the market who sold batteries, and would replace them for me. However, he retired.

There is another younger chap doing it, but he charges (?) lots more, and does not seem to be so careful about removing the back of the watch without risking damaging the watch. I could probably do a better job of it myself.
My question is this (yes, there is one): where do you buy your batteries for watches? On-line? I would like to get a reputable brand like Duracell, rather than risk the battery leaking etc, and spoiling the watch. I have looked on line, and they all seem to use different numbers to identify the size of the battery. If I start with a reputable on-line seller, then I could work out the size from their numbers. Any assistance from the sensible peeps on this thread is appreciated.
