User blog comment:MilitaryBrat/Master Chief vs Xenomorphs/@comment-4749025-20120204030950/@comment-181289-20120204044442

If the Sheilds are knocked down they will power back up in a few seconds, you can't permenatly get rid of Elite or Spartan Sheilds. If they armor is destroy I don't think you have to worry about your sheild any more, you praobly already be dead.