Got to work on the R80 again during the past months, so here we go:
Welded my battery + electronic box out of some V4, which fits in the original battery holder behind the airbox. It was quite a tight fit but I made it work eventually.
Then I received my Braille Motorsport battery, which seems to be a quality product so far. With approximately 6 pounds it weights less than one third of the original battery. I can't say much about how well it lasts, because I haven't ridden the bike much yet, but I'll make sure to add a review here in a little bit.
After fabricating all kinds of brackets for the wiring in the box, I painted it and installed everything on the bike.
This is the last post before the final update so make sure to check right back to see it finished.
Cheers.