In a teardown that's otherwise been a breeze, we've encountered our first real repair barrier. Overly sticky battery adhesive. Decidedly the worst kind of adhesive, this is the kind that requires effort to remove. Yuck.

The Lithium-ion Polymer battery in the Kindle 7th Generation is rated at 3.7 V and 890 mAh. That works out to 3.29 Wh of energy.

Amazon tells us that's good for 4 weeks of use, defined as reading half an hour a day with the Wi-Fi turned off. That's 14 hours of use and 658 hours of standby.

Sounds like a lot! But it's half the eight-week spec of the Kindle Paperwhite, a backlit tablet with a 5.25 Wh battery. Where is this Kindle's extra power going?