How long does the longest-possible total solar eclipse last?

This is about 7.5 minutes. The longest total solar eclipse from 4000 BCE to 8000 CE, a span of 12,000 years, will occur on July 16, 2186 and will last 7 minutes 29 seconds.  Its path sweeps across Colombia, Venezuela and Guyana. The August 21, 2017 total solar eclipse, by comparison, will last a maximum of 2 minutes 43 seconds.   About 70% of eclipses last longer than this.