There a many who scream that this or that is THE way to charge lithium batteries. But the thing is I've never had a lithium battery in any phone, tablet, Kindle, or any other device fail (go dead) before I replaced or retired said device. Even those I've used for 4+ years have never had a battery die. I think the important thing is to not routinely let it drain completely. Use common sense. Make a habit of charging the device before it gets too low. And don't leave a device always plugged in to a charger. Use common sense and the battery should outlive your interest in using said device.