Damn battery rot

Hi, I was sorting through my stack of IBM XTs & ATs when I saw what I thought was condensation on the case of an AT. Strange I thought I hope that's not rain water (being indoors!) I opened up the case and was dismayed to fine the remains of a back-up battery and a large puddle of horrid looking gunk eating a hole through the steel case. Turned out the previous owner had put a cheap back-up alkaline battery in place of an expensive lithium battery, although the sealed plastic box they came in made no mention of possible leakage. Anyway I cleaned it all out and made a mental note to check my BBC Master's didn't have any batteries left in them either. Just a word to the wise, I'm sure most of you are thinking 'been there, done that'! Regards, John