Phone batteries are advancing but not nearly as fast as phone technology. If you were to take your phone and talk on it constantly right after a charge, you'd expect 6 hours or more. That's light years ahead of where we were 5 or 6 years ago.

Unfortunately we expect more than ever from our devices. They're constantly connected to the data network and constantly being tapped and used as gaming and work devices. Would you ever expect your laptop to get you through an entire day of constant use?