Quote:
Originally Posted by Waylander
Sorry if this has already been answered elsewhere. I have a PW 4 that almost a year old, and am slightly concerned about the battery. I've noticed that when the power light goes green, it's still on 96-97% or so and takes forever to get to 100%. I charged it to 100% last night, unplugged it and didn't use it for a couple of hours, and when I turned it on it had already dropped 2%. After 1-2 hours reading since last night it's down to 94%. I'm probably worrying about nothing but it this normal behaviour?
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This is routine behaviour for lithium-ion batteries. The charging circuit moves further and further into the trickle-charge regime the fuller the battery gets, because the closer the battery is to full, the more likely that fast charging will cause gas production and then the lovely thing the battery engineers call "venting with flame". I think the green light means "switched to trickle charging, further charging will take ages, you might as well start reading again", but really the meaning of that light is completely opaque and always has been. Why does it flash when you turn the kindle off and when you turn it on? Search me...
The "drop" when turned off is partly the result of the Kindle actually still being on (though not doing much) even when turned "off", but mostly an illusion caused by the battery meter not being entirely accurate. It's based on examination of the output voltage of the battery, and at both ends (empty and full) very much has error bars of a few percent. Also, the battery is naturally going to self-discharge a bit when it's that full: full batteries are unstable systems and very much want to be emptier. (When the battery really starts to wear out, the meter can jump by 50% in an instant as the battery circuit suddenly realises how much less charge the battery holds than it thought it did.)
Also, honestly, a 3% drop in two hours would equate to over a *hundred hours* of reading time. This seems most unlikely: you can expect to get 20--30 hours on 11 before needing a charge. You'll never get a hundred hours of reading on a single charge even on a brand-new Kindle with the light on zero. So if anything you're seeing remarkably *low* battery drop rates (likely because the battery is so full, and it can produce more charge before reducing its output voltage much), and you'll probably see the rate of drain pick up as the battery empties.
(The most extreme Kindle that I know of in this area is the original Oasis. If you turned the light off, a fully-charged charging case could sometimes keep the thing going for *fifty* hours.)