2001 V70T5a stops dead in intersection, all power off, starts normally the next day

[hankbates]

208k miles, was running fine over the last year or three. When I got to the car (wife was driving) there were no lights,wipers, absolutely no nothing. Battery still normal charge, no other checks made.
Met the tow driver today at the car, it started up normally as if it never happened.
Car was driven 3 miles from cold yesterday, hot day, no rain, high humidity.
Only prior electronic problems involved the alarm ten years ago, etm about 8. Both fixed.

When starting the next day there was no indication of battery weakness or terminal issues.
When I left it the day before the wipers didn't work, the interior lights would not come on, etc.

No sign of corrosion on terminals.
When jump start was attempted while in the middle of the road there was no response, the car acted as completely dead even with jumper connected.
Car started right up the next day from the battery as normal
What would cause the electronics to completely disconnect the electrical system while driving, and reconnect it a day

[abscate]

Check the main feeds from the battery to the fusebox. Sounds iffy in there

[packetfire]

Remove the battery, and check the "hidden" panel of massive fusible links as described here:
https://www.matthewsvolvosite.com/2001- ... eshooting/