voltage

I'm writing in trying to identify what exactly is failing. Have had this trouble for a while, where I leave the car for a day or two then it simply won't start. I accessed the UB readings today and found that when everything is off, it reads around 11.5 V. When I turn ignition on, the voltage...

This happened every day for a week, then nothing for 500 miles, now it came on again so I was determined to record it because it's always been so quick that I don't see the exact message. (occurs about 1:04) the A also drops too, not sure what should be normal. It drops to -50A when starting...