By
updated 1/22/2013 11:53:00 AM ET 2013-01-22T16:53:00

As we use our smartphones for more than just calls--GPS navigation, email, Instagraming an epic hipster mustache--having an external battery has become a necessity. But lugging those bigger batteries around is a pain, and can take up valuable gear space. Especially on a hike or climb when every ounce counts. That's why the brain power [...]

© 2012 Discovery Channel

Discuss:

Discussion comments

,

Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments