Thinkpads are great, especially the old ones. You find a T420, and you can have a battery hanging off the back, a battery in the optical drive bay, and for some old Thinkpads, there’s a gigantic ‘slice’ battery that doubles the thickness of your laptop. Here’s the most batteries in a Thinkpad ever, with the requisite reddit post. It’s 27 cells, with an all-up capacity of 212 Watt-hours. There are two interesting takeaways from the discussion here. First, this may, technically, be allowed on a commercial flight. The FAA limit is 100 Watt-hours per battery, and the Ultrabay is a second battery. You’re allowed two additional, removable batteries on a carry on, and this is removable and reconfigurable into some form that the TSA should allow it on a plane. Of course no TSA agent is going to allow this on a plane so that really doesn’t matter. Secondly, the creator of this Frankenpad had an argument if Hatsune Miku is anime or not. Because, yeah, of course the guy with a Thinkpad covered in Monster energy drink stickers and two dozen batteries glued on is going to have an opinion of Miku being anime or not. That’s just the way the world works.
Prices for vintage computers are now absurd. The best example I can call upon is expansion cards for the Macintosh SE/30, and for this computer you have a few choice cards that have historically commanded a few hundred dollars on eBay. ..