CHECK or REMOVE your old BATTERIES

[Tetsuwan Convoy]

Has anyone ever experience leakage/corrosion with watch batteries though? Cos I've only experienced it with non-watch batteries.

I have, I assume you mean the LR44 or whatever they are ones. I had some leak. I had taken them out before hand. They seem less likely to and the damage doesn't look to be as bad as the larger batteries, but they can still leak.