Jornada 820 battery repair experiments

Just a little update and a mostly happy ending to my 820 battery modding: After soldering in the 4000 mah batteries, I have not charged the thing since September 12th and have used it a little bit--office stuff, reading, and little games-- every day since. It's still over 60 percent full! The occasional bogus 30-minute warning is a small price for this kind of endurance.

Just attempted a recell for this, managed to fit two 4000mAh Battery (model num 606090) into this (PCB slightly tilts up for the battery on the right, thats fine though)

My fuse was of course dead, but suprisingly you can still get these special fuses from Aliexpress (search 10PCS SFC-0405B, not sure if I can post links but PM me if needed)

Soldered it on quickly as to not trigger the fuse's thermal cutoff, plugged it in, and the red light comes on as well as charges!

If you plan on doing this, just a note, the adhesive holding the plastic together is strong (as well as the battery adhesive, very strong), and the 26 year old plastic is very brittle, it will snap if you apply force (had to JB plasticbond weld it back together)

The battery fully charged at 8.4v reports 30%, but during charging was anywhere from 46-70%. So maybe overtime it'll calibrate?

I preemptively tried some registry edits to disable the battery warning, so we'll see if that works or not and I'll update this post.