Thursday, December 20, 2012

Power for the Travelling Kindle

How to keep your Kindle charged while on a trip? Although the Kindle E-readers- the basic $69 model, the Keyboard, and the Paperwhite all have battery lives 15 to 30 hours, the battery life drops if you have wireless on and if you use the frontlight on the Paperwhite. And the Fire and Fire HD tablets have a battery life of 5-10 hours, depending on how you use them. So you're going to have to charge them- even if only once a week for the E-readers and

All Kindles come with a USB cable which can be used to charge the Kindle from a computer USB port or any charger with a USB port. Amazon doesn't include an AC wall charger, apparently assuming that everyone has a USB charging port available.

There's a couple of problems with that when you're on a trip. In order to save the computer's battery, most laptops don't provide power to the USB ports when they're off, even if connected to a power outlet. And leaving your computer on all night to charge a Kindle is overkill.

Also, computer USB ports produce limited power. The most common USB port, USB 2.0, produces 500 milliamps (ma). That's enough to charge a Kindle E-reader overnight but the Kindle Fire needs more power. Also, computer USB ports don't always provide the maximum amount of power- the power available depends on other devices that are requesting power, some of which may be internal.

The solution is an AC charger with USB charging port. A charging port, unlike a computer USB port, always supplies the maximum amount of power. Amazon sells two USB chargers that are designed to work with the USB cable supplied with your Kindle or a replacement cable. The Kindle US Power Adapter provides enough power, 1000 ma, to fully charge the Kindle E Readers in about 4 hours. The Amazon Kindle Powerfast produces 1,800 ma and charges the Kindle Fires in 3 to 5 hours, depending on the model.

Note that the Kindles maximum charge rate is set by the device to prevent damage to the Kindle battery, so if you charge a Kindle E-reader on the Powerfast, you won;t damage the Kindle but it won;t charge any faster than it would on the Kindle US Power Adapter.

If you own both a Kindle Fire and and a Kindle E-reader, get the Powerfast because it will charge both Kindles as fast as they can safely be charged.

If you'll be in remote areas away from AC power, there are other ways to charge Kindles, including car USB chargers and solar chargers- I'll cover those in a later post.