Crack the battery case open and replace the cells. It's especially easy on 486 and early Pentium notebooks, because those usually use nicad or NiMH cells... you can find those cells dirt cheap, and since there's no fancy charging circuitry involved (unlike lithium ion), it doesn't even really matter if it's exactly the same kind of cells, so long as you put together something that adds up to the right voltage and fits in the space required.

^^^ this ^^^

ni-cd batteries are relatively cheap from china. (or li-ion or whatever). Granted the laptop has to be worth the investment. Most aren't.

There are companies on the web that will re-cell any laptop battery (send it in and they will check it out). Most people don't want to pay the cost for this.

I collect old laptops (mostly IBM Thinkpads) and I still have early Pentium models (760 series and 770 series) with working batteries (and I don't mean 5 mins operating time). You are much better off just using a power brick unless you realy want to be out and about running DOS or something crazy.

Yeah, my old machines are more "portable computers" than "laptops" - not only are the batteries dead, but I find myself preferring a PS/2 mouse to the nub, and there really is no point to use them on the road without WiFi capability.

I really hate those crappy ni-cads, I wonder if tossing them in the freezer might reset the memory effect that they have to some extent.

i know the ones with cells in them can be rebuilt with new cells.

cdoublejj wrote:

i know the ones with cells in them can be rebuilt with new cells.

Almost all can be rebuilt except for the newer lithium polymer batteries, you can crack open the pack your self and check it out. You could rebuild the pack by just salvaging the cells from other packs but you got to get the voltage right. I do remember seeing a few videos on youtube how to rebuild them. Even batteries from older macs can be rebuilt but you got to get the right cell type then get the right number of cells then all is set.