Most technologies have changed beyond all recognition in the last 10 to 20 years. Compare a smartphone from 10 years ago with the latest iPhone, and the difference is night and day. Laptops, TVs, cameras … pretty much any technology you can name has transformed almost beyond recognition. But there’s one technology whose pace of development seems truly glacial: batteries.

I’m not suggesting battery tech hasn’t improved at all, of course, but my smartphone 10 years ago got me through a typical day with a bit to spare, and my iPhone today does pretty much the same (albeit in a significantly smaller package). Those tiny fuel-cell batteries they keep promising us, with smartphone and laptop battery-life measured in weeks and not hours, seem as elusive as ever. Until that glorious day arrives, there will be times when our iPhone or iPad just isn’t going to have enough power to cope with an extra-long day, weekend camping trip, or similar.

There are a couple of different approaches to the problem. The first is a powered case. We previously reviewed the Morphies Juice and Air power sleeves. This is ideal when you know in advance that you’ll need the extra power and don’t mind a bit of extra bulk to achieve it. The second approach is an external battery pack you use to recharge your phone (and other USB-interfaced gadgets) when needed, or when you’re in one location for a while.

This is the approach taken by the Digital Treasures Powerflask, a cute-looking pack that can simultaneously charge an iPad and either one or two iPhones … expand full story