South Korean Professor Cho Jae-Phil of Hanyang University and his team have developed lithium batteries that are 90% more efficient than current models.  You will be able to do stuff 8 times longer – cell phones, notebook computers, cameras, etc.  They replaced the graphite in the batteries with three-dimensional porous silicon particles.  Professor Jae-Phil has hinted at merging this technology with solar panels.  For More Info:  Hallyutech.net