@ KennyR

Thanks KennyR - very minor point - the video is by someone calling themself "TheiBookGuy", as I say it's a very minor point, but great advice in the video.

It's made me realise that if I can get the batteries cheaply enough I'll go about fixing the "ded" batteries I already have, and keep the housing and the usefulness of the housing, and just recycle the "ded" batteries from inside the housing itself, and that way keep my systems working as I want them to.

That's - even if I can't commercially buy new battery packs anymore - especially the 17" PowerBook batteries which seem to sell for over £100 when new, which is a bit ridiculous, and so keep my batteries in tip-top condition at a reasonable price.