It didn't take long to get to the heart of the Voyage. This reader is powered by a 3.8 V mixed metaphor battery rated at 1320 mAh.

We apply some oomph in the form of a Plastic Card to free the battery from its sticky patch.

Amazon boasts that its Voyage will last up to six weeks on a single charge. For comparison:

The Kindle (7th Gen) claimed a useful life of up to four weeks from its 890 mAh unit.

The more versatile Kindle HD 6's onboard reactor weighs in at a whopping 3400 mAh, but it's rated for just 8 hours of normal use.