2003 5.3, 250K miles, one year old 200A alternator from Quick Start, three year old battery from Odyessy (NOT Optima). New battery cables last year. The engine cranks very well and starts without issue. Volt meter always at or above 14V. Everything would be fine then with no warning, the tach would go to zero, engine power is gone, the battery light would come on and the DIC would display "battery not charging". This only lasts a second then the display and light go away, the tach comes back and the engine continues along. NO CODES. This could go on for a while, every few minutes it happens. Then it won't happen for an hour. Common sense and experience say if the battery or alternator were bad, it would be continuous, not intermittent for such a short period of time then not happen for many miles driven. I have a 160A alternator on a shelf I'll sway in in the morning but I can't imagine that's it. Any ideas?