Car lost all electrical while driving

I had a similar incident many years ago, lost all power, pulled over, checked both battery cables, etc. Car did start again after about 20 minutes of trying to determine the cause, then did the same thing a few days later. Turned out to be a short inside the battery, a plate had apparently come loose from vibration. It was a new Die Hard, replaced no charge. I have also seen the factory voltmeter cause similar issues.