User blog comment:Itachou/The Missing Link overview/@comment-4409563-20110921184022/@comment-1984897-20110921214406

Details are sort of fuzzy, but according to one of the ebooks, basic mechanical devices (like limb replacements, artificial organs, the SHS) are powered by small naturally generated electric charges from the human body. This explains the musculature theme of most Augs; they are artificial structures that act similar to animal muscle tissue. Only the not-necessary Augs such as arm-blades, invisibility etc require stored external energy cells. This also somewhat explains why Adam doesn't collapse when hit by EMPs.