Charging a Fujitsu P-Series (Centrino-based) currently running 98, with a number of vintage office apps for general work on-the go, as it's on the small side. The Fujitsu's battery is effectively unavailable online. I have a poor track record at getting these glued battery containers open in a less destructive way, but I have hope I'll figure it out.
It is a tad on the heavy side for my intent, which is having it with me to do writing on the road/when I'm resting on walks/wherever. It weighs about 3 lbs and has a 10.6" screen.
The Fujitsu also runs 98 pretty well, which means I can run most of the DOS apps I want for this little project. The original battery life was 7.5 hrs, this one seems to be between 1 and 1.5 hrs. So, a bit reduced.
If I figure out how to rebuild the original with 3500mAH 18650s (a total hack job as it looks like the originals are 18350s or something similar, and so I'd be using 3 long batteries in place of two rows of 3 short batteries. There's enough room in theory if I get the wiring right the first time. 😀 Also a 7.5 hr battery could be a 17 hour battery when I'm done. If it works (if I do it) I'll probably get hooked on rebuilding batteries. A 17 hour win98 laptop?
I think I'll put that 139th in line on my project list, right after fixing the screen on the Toshiba T1200.
Edit: It occurs to me that building a battery bank to replace the wall power (in this case 16V / 3.75 A) might be an order of magnitude less complex. Probably doesn't even need 3.75A if it's not charging another battery. This could easily apply to other more vintage portables. Tenergy made a "universal" laptop power bank from 5 to 19 volts, but it appears to have gone the way of the dodo.