I have a backpack designed specifically for laptops. It has a zippered lid with a zippered compartment in it on the top (for batteries) and three layers of pouches for documents. I just weighed it — 25lb.
It currently has an Apple 'Pismo' laptop in it. That model lasted a while, it was the last one with two swappable battery/disk drive bays. You could A-B two batteries or have a floppy or CD-ROM drive. I don't know if it even starts up now.
Have patience, eventually the computer will reduce down to a headmount camera/display of some sort and a hand-held stylus.