Yeah so I saw this page, he's selling the CR2032s with welded on tabs, thought those would be great for replacing all my batteries, but he's in the UK, and the price is kinda high. I'm in the US, anybody else know a good source for these?
Mouser has a good selection of them, Digikey has one type. There was a thread about it here a little while back, someone might've said none of them were exactly the right size though (I don't recall - search feature is repaired now, so try it, heheh).
Consider using battery holders, so that you don't have to desolder and solder batteries off and on.
Lithium coin cells tend to destruct if they get too hot, especially when being soldered. And they only last a max of 10 years.
I think at the low currents involved the oxide coating on a battery holder would block the battery output. I've soldered button batteries with no problem (not sure about lithium). I sand down a spot and goop on a glob of hot fresh solder and it sort of sticks to the shiny sanded parts.