From: http://www.batteryeater.com/news.html

  Battery Eater Pro 2.70 BEPro.exe is a testing tool intended to reveal the potential of a notebook
  battery pack. 
  Battery Eater can measure the minimum operation time of a notebook (when all power-saving options 
  are disabled) under conditions close to the maximum workload (Classic mode). 

Review: http://www.makeuseof.com/tag/benchmark-laptops-battery-life-battery-eater/

  The program automatically generates a report once your computer’s laptop battery can endure no more
  This report is filed in your Battery Eater installation folder and is labeled with the date that you
  ran the benchmark.