Board Thread:Game Discussion/@comment-9304379-20130521083744/@comment-153.25.178.61-20130521121357

I will second that, and add the short version: without energon, you can't do anything unless the bosses pop up from people asking for help.

NOTE: Energon recharge is 50% of your total - so if you have 100 energon, you get 50, but if you have 200, you get 100. ie: These energon recharges will be more valuable as you level up.