What are the differences between Energy Saving mode and Constant Current mode?

Energy Saving Mode (Mode 2 - 13 second hold and 2 blinks) – Will start in Power mode at 100% for 2 minutes and then drop down to 50% for the next 25 minutes. Once it hits the 25 minute mark it will drop another 15% until the batteries run out. So this mode will maximise run time.

Constant Current Mode (Mode 3 - 16 second hold and 3 blinks) – Will hold 100% at power mode for 2 minutes and then after 5 minutes it will drop to 75%. The 75% power will last until the batteries are empty.