Justin Portable Power Products
© 2014 Innovative Technology Electronics Corp.
Increasingly, carrying an extra power supply is becoming a necessity, for teachers and students alike, and the past 12 months has seen an increase in form factors, with an associated drop in price. All of these options are powered by powerful, light, lithium-ion polymer batteries, and all require cables and external adapters to be charged. They can also charge from your computer's USB port by way of a Micro USB to USB 2.0 cable. Here are three current (as of Fall 2014) options that are typical in terms of price and features. We tested each on both iPhones and iPads with success, but as you can see, their charging ability varies as does price (ranging from $20 to $70). We recommend shopping around and checking for the latest prices and features The most portable and straightforward is the $20 Justin Round Power Stick. About the size of a shotgun shell, it comes in black, silver, red, pink and blue and has a two color LED indicator light. It can store 2,200 mAh; enough for one smart phone charge or a partial iPad charge, providing you have your cable. At just $20, it's the best option for student's backpack. The $70 rechargeable iPhone 5/5S case doubles as a protection case and stand. It can store two phone charges, and roughly doubles the size and weight of your iPhone 5. It blocks the earphone jack, but a special adapter dongle is included. It also hides your lightning cable access, so you'll need to remove the phone every time you want to do a manual sync with a computer. To charge both your phone and the battery, you'll need the included MicroUSB cable. The most powerful battery we reviewed is the $30 Power Bank, that doubles as a device stand, in case you want to watch movies or video chat while charging. It can hold 6,000 mAh -- about three full iPhone charges. Know that Moore's Law is affecting this category greatly. These same batteries one year ago would have had roughly twice the price. So shop around and check the competition.
$2070, iPad, iPhone, Android, Nook, Kindle
Teaches: a power supply for tablets or smart phones