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.
If it has a removable battery, then it’s likely made up of 18650 cells. If it isn’t then it’s likely a flat lithium cell like a phone.
I pulled the battery case apart and snipped all of the 18650s out and charged them in a dedicated charger. They had been sitting too long and some of them were far below where they should be. It was causing the laptop power adapter to shut off.
Once they were properly charged they all tested good again. I could buy new cells, but I think these will work fine for what it is.
Now I need to spot weld metal tabs back onto the cells, put it back together, and hope it works.