i was posting all that info because i'd just opened up an amiga 500 for the 1st time. wanted to see mostly what battery it took and if it could be replaced and what the exact model #'s were on all the chips. also was trying to replace some keys in a professional way but looks like Amiga 500 has the weirdest keys ever and they don't really pop in and out like keys on other keyboards. that battery hack sounds interesting.
that old one was stuck in there really well though. it didn't appear to be corroded yet at all so i don't think replacement is critical, but im doing it anyway. for the keyboard i saw at least 1 listing on ebay for just the keyboard part which is the easiest thing to replace in the amiga 500. if i can't get it cheap then it's not going to matter much since i'm not using it for word processing.
after finding a battery: It's strange it's a rechargable rather than lithium. Yes the crap that comes out of especially Ni-CD is really bad. Also for the gentleman who made this suggestion I have a question; it has 2 metal things on either side that appear like the 2 contacts that pinch the battery in place, but the battery didn't seem to want to come out of those and it didn't seem corroded so i didn't take it out yet. but have ordered a definite, claimed to be brand new replacement for that horribly strange battery in there (horrible as in not at your local radio shack but id already seen a listing for it on ebay and it was like 5 bux shipped so i couldn't turn it down).
It looks like in the picture they show in the listing that what I thought were contacts are actually part of the battery. Do you carefully but forcefully yank the old one out? Then it comes out with a prong on either side sort of. And no I definitely don't think solder is needed here at all like you say.