Quote:
Originally Posted by HarryT
I would have thought that, if anything, constantly using the wall charger would shorten the battery life rather than lengthen it. I always try to let my Reader get down to 1 bar of charge before recharging which, for me, means that I charge about once every 3 weeks.
|
I think the net wisdom (batteryuniversity.com, wikipedia, etc.) on LiIon and Lithium Polymer batteries is that frequent, shallow discharges are better than rarer, deep discharges with regards to service life. I.e., the battery will be in better shape after 600 half-discharges than 300 full-discharges. And what really kills laptop batteries is heat. When operating on AC, the average laptop dumps so much heat into the battery that the service life of the battery is affected more by that heat than discharge/charge habits.
Now my guess, and it's only a guess: The Sony's battery life is extended by operating on AC. The charger tops off the LiIon battery and then turns off. After that the Reader is operating on AC and it is so low-powered that the heat dumped into the battery during operation is negligible. So by operating on AC you're not using up discharge/charge cycles, thus extending the battery service life.