Lifespan of a black hole?
If we assume we are talking about a black hole of average size it would take roughly 1.2x10^67 earth years to die out.
(aka 12,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years) Answer
Steven Hawking has theorized that Black Holes emit "Hawking Radiation" and that the rate of emission is proportional to the cube of the hole's mass. This implies that they are evaporating and will, at some point in time, disappear. Large black holes (mass greater than the sun) will essentially last forever, this falls to 2 to 3 billion years for masses of10 11 kg. To get down to a black hole with a life span of 1 second, the hole would have to have a mass of about 2.28 × 105 kg. The recently constructed LHC in Europe was supposed to have the potential of creating mini-black holes, but these would evaporate almost as soon as they were created.