The Prologue:

I'm trying to fix this laptop, which refuses to turn on without presing the button many times, then it complains about the CMOS settings.
I suspected the backup battery, but didn't know where to find it or what type it was. I couldn't even get inside the thing at first
Here is how I eventually got into it.

	W00T! Looks like I found the battery, or rather, two of them. One six-cell and one three cell. My guess is that the larger one is the one which keeps it alive when you put it to sleep and do a quick battery swap, and the smaller one is the backup. I think I'll take a closer look...
	Eeeew... what a mess! What's all that blue cack I wonder. (Copper Sulphate?)
	Lovely clean connections. NOT! Those are on the smaller battery, with the three way plug.
	The other one was worse. Not obvious from this picture is something that's missing from the next...
	Oh dear, that doesn't look so good. I figured I might be able to remove the plastic from the two way header, and solder the battery directly to the board
	Then I noticed this little mess.
	The header pretty much fell off Q30 was nowhere to be seen, (or so I thought until I was looking at these photos again and noticed that it's there in the first two) and D40 and D41 fell off as I was cleaning it up.
My guess is that something was spilled in there, (see the ventilation holes in the first picture) and the batteries discharged through it over a long time, causing some kind of electrolytic reaction.
	At this point I decided it was probably futile trying to reconnect the larger battery, as I had a feeling it needed these components to function correctly. Also, since there's only one main battery, the staying alive thing is irrelevant. So, I cleaned up the connectors for the smaller one, reassembled it without the large one, and bugger me! It started up right away. M0RE W00T!

I suppose I ought to take it apart again later to see if that battery is taking a charge. at least I have six spare cells just in case.

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Update. Six spare cells. Yeah, Right. :-(



So, since they're 'normal' rechargeables, if I can't find anything the right size I will probably use something like a battery from a cordless phone, made from three small NiCd or NiMh cells, and wire it directly to the header.

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	Well, I couldn't find exactly the same battery. There was a choice between a smaller one or a larger one. I went for the larger one since I thought the charging current might be too high for the smaller one.
	It lives again! That's it running dsl