I hate to contradict all the opinions about LED energy use but after four days since the last full charge I've only used about 15% of my battery energy. I use the PW with WiFi on, Page Refresh on and the PW at level 22 of the 24 possible.
Of course SOME energy is used by the LED's but it has a relatively negligible effect. I read for about 2 hours per day on the Paperwhite.
I've seen others here say they have to recharge their battery every other day and keep their PW light level at 8 or less all the time.
I won't do my next full charge until the PW gives its 15% level signal.
I worked on the 75% charge at the time I received the unit for 2 days loading in ebooks and allowing them to index and just experimenting with all the controls. When I finally did the full charge after two days, it was only down to about 40%.
I also found that one MUST leave the PW light level at 22 to 24 to keep the screen appearance as bright white with great font contrast. I tried reducing the light level to 8 in pitch dark rooms but it changed the screen to yellow with low contrast. Thus, I now use level 22 from bright sunlight down to pitch dark. I find it the best way to read on the PW. I find that level also eliminates all glare from the sun or overhead lights in contrast to the Kindle Fire where glare is a big problem even with the anti-glare screen.
I've seen others here stubbornly stick to low PW light levels and constantly complain about screen defects. They refuse to raise the light level for even one day to see if the "defects" disappear. There is no question that at low light levels all the warts on the screen get amplified. It would be like watching your LCD big screen TV from one inch away with a magnifying glass and getting demoralized by all the pixel "defects."
The last 4 days I have only been reading eBooks. There is no way I would use the PW light at less than 22 (the Amazon default shipping level) even if I could gain an extra day or two of charge.
I like the idea that, when one closes the cover, the PW goes to sleep and then reopens at the same page. In Bible studies where one jumps all over the NIV Bible and then has long discussions, this feature is ideal to preserve battery strength.
Last edited by sirmaru; 10-10-2012 at 08:18 AM.