I just got a pretty good deal on an old ThinkPad (think 10 years old now) to use as a beater for screwing with ArchLinux and hopefully to find a real use for. It’s in great shape like it was never really used, but big shock, the battery is at 50% effective capacity and what’s there disappears in less than an hour.
Would you bother buying a battery replacement for it? On one hand I want it to actually be usable on the go because that was sort of the point. On the other, while replacement batteries exist, I’m worried that they’re already very old themselves and already “expired”. Would you take the chance? I don’t want to let this thing go to waste when it’s still perfectly usable, in fact it’s pretty fast.
I’m a bit metal, any time a laptop dies I strip it for parts and keep stuff like the 18650 cells. If I had a laptop which desperately needed new batteries, I’d probably find cells in my collection with around the same voltage (or better yet, a parallel pack I can break apart), rip open the laptop’s battery, and replace the cells. I don’t tend to be on the go very often though, so I’ve never needed to do that. This is assuming the laptop uses li-ion chemistry, otherwise a lot more work would need to be done. In a pinch, brand new 18650 cells are really cheap
For something that old, unless you were using it as a thin client or something it might be better to use it as eg a home server, that way it doesn’t need the battery to be any good because it’s plugged in 24/7.