5-Hour Energy Inventor Likes 'Toiling in Obscurity'

In general, Bhargava is an entrepreneur who taught himself not to worry about too much, including frills. The billionaire's office is undecorated to the point of drab. He said he gives away close to 90 percent of his money to charities in India.

Bhargava lived in India until he was 12 years old, when his father moved the family to the Detroit area. Good at math, Bhargava got into Princeton, but finding it pointless for him, he quit after one year.

Sports Drinks Science: Is It Hype? Watch Video

Energy, Sports Drinks Rot Your Teeth Watch Video

Caffeine Inhalers to be Investigated Watch Video

But for a guy who seems to take it easy, he is pretty competitive. His many imitators, who seemed to think it was about the bottle size, have made almost no dent in Bhargava's market share. He owns this energy shot market, but what he doesn't own are fancy cars or houses, because he said in India, he was taught to "be practical."

"The more you consume, the more insecure you are," he said. "It's the nature of the world. The simpler stuff. If your mind is still, you're the happiest."

Right now, that will help, as what's in the bottle is a question getting government attention even as it sells and sells and sells.