Humans have a limited battery life!

PatentYogi_Humans have a 12-16 hour battery life

A lot of research has gone into increasing the capacity of humans to do physical work. This includes development of exoskeletons.

The first exoskeleton was invented and patented in 1917 by a US inventor Leslie C. Kelley. The exoskeleton operated on steam power with artificial ligaments acting in parallel to the wearers movements.With the pedomotor, energy could be generated apart from the user. 

Patent Information
Publication number: US1308675 A
Patent Title: Pedomotor
Publication date: 1 Jul 1919
Filing date: 6 May 1919
Inventors: Leslie C Kelley
Original Assignee: Leslie C Kelley