Lifespan of LED bulbs - Page 2

murraypaul · 10-09-2012, 10:01 AM

Quote:

Originally Posted by sirmaru

Current drawn by the Paperwhite is from opening the unit and turning pages - NOT from the LED use. You can keep it at the maximum of level 24 and not change the battery life one iota.

Sigh.
This is of course not true.
Powering a light takes energy. That energy comes from the batteries.

Popup · 10-09-2012, 11:29 AM

Quote:

Originally Posted by murraypaul

Sigh.
This is of course not true.
Powering a light takes energy. That energy comes from the batteries.

Of course. I desperately hope that nobody here believes that the LEDs can operate without a power source.

What is in dispute is how much power they need. I haven't received my PW yet, and I wouldn't take it apart just to measure the current, but I'd guess that the current draw per LED is on the order of 1mW¹. Given that there are eight LEDs and the battery is on the order of 6Wh¹, that would translate to about 750 hours of light-on, if everything else is powered off. Clearly that's not the case, but it appears that Amazon's claim that the lights consume significantly less than the rest is not patently absurd.

¹Figures obtained through the time-honoured method of 'Pulling them out of the arse'™. Any real figures greatly appreciated.

murraypaul · 10-09-2012, 11:49 AM

I suspect they must use a measurable amount, otherwise Amazon would advertise battery life figures with the light on full, rather than at setting 10 as they do now.

HarryT · 10-09-2012, 11:59 AM

Quote:

Originally Posted by sirmaru

Current drawn by the Paperwhite is from opening the unit and turning pages - NOT from the LED use. You can keep it at the maximum of level 24 and not change the battery life one iota.

Oooooh - a magic light that uses no power. Cool!

Iznogood · 10-10-2012, 01:43 AM

Quote:

Originally Posted by HarryT

Oooooh - a magic light that uses no power. Cool!

That's the next generation kindle - it's not for sale yet.
I'm guessing that within the year, Amazon will present The kindle firefly. Illuminated without draining the battery. Warranty void if you forget to feed it regularly

sirmaru · 10-10-2012, 08:03 AM

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.

haydnfan · 10-12-2012, 07:18 AM

It's not about being stubborn sirmaru, you are just flat out wrong. Raising the light level makes the defects obvious, they are not obvious at lower settings. And that is NOT why we use a lower setting. Some people don't want eye strain from bright light, else we would all use a tablet for reading.

Now you don't get eyestrain from reading on a tablet, fine my parents are the same way but I do and many other posters do.

I also have decent battery life, I think that the problem with the other PW owners and battery life is related to indexing and not the light.

xendula · 10-12-2012, 08:21 AM

What haydnfan said.

Plus, simaru, you don't read in the dark at all, so naturally, if you sit in a well lit room, or read during the day by the window, you are able to use a higher light setting. Not everybody has the luxury of reading time during the day, you surely can see that, no?

Many users here read in the dark in bed (crazy idea... I know....) often with someone sleeping next to them.

The PW was not made for daytime only use. Amazon built lower light settings into it for use in the dark.

sirmaru · 10-12-2012, 09:00 AM

Quote:

Originally Posted by xendula

What haydnfan said.

Plus, simaru, you don't read in the dark at all, so naturally, if you sit in a well lit room, or read during the day by the window, you are able to use a higher light setting. Not everybody has the luxury of reading time during the day, you surely can see that, no?

Many users here read in the dark in bed (crazy idea... I know....) often with someone sleeping next to them.

The PW was not made for daytime only use. Amazon built lower light settings into it for use in the dark.

I read my Bible early each morning on the PW with a light level at 22 of the possible 24. It is in a very dim light environment then but not pitch dark. It seems clear and bright white to me at that time.

I did my last full charge on Oct 6 and my meter shows about 50%. Thus, it looks like I will get about 11 days to the 15% signal. I leave WiFi on all the time and use Page Refresh on.

My Kindle Fire 1st Gen used to get 5 or 6 days of battery use to the 15% signal. I also charged that on Oct 6. Its at 62% now so I will probably get 11 days on that until the 15% signal since I don't use it as much for reading since my PW was received.

My Kindle Kbd 3rd Gen WiFi gets about 35 days to the 15% signal.

I find reducing the PW light level to level 15 in that low, early morning environment is also suitable. I just tried it after reading your post. That also seems a suitable level for that environment.

I still think PW light levels have zero, SIGNIFICANT effect on battery charge life. To determine its real effect, one would have to run a full battery charge level down to the 15% level with a constant PW light level for each cycle and see how many days the battery lasted. Frankly, I really don't care if it did change the cycle length by a day or so. Its irrelevant to my needs.

Battery life collapse has never been the reason why I've discarded gadgets which use Lithium batteries. Obsolescence is the main reason I drop old gadgets.

Amazon just posted how their model Paperwhite looks at different PW light levels and different environments here:

http://www.amazon.com/gp/feature.htm...d_i=1000841011

If one looks at those pictures, one will notice that in a dark room at PW level 5, the screen has a BLUE tint. That is what I have been stating over and over in other threads. At low PW light levels all the screen defects become highlighted. The Amazon displays with high light levels (3 pictues there) of 20 and above, show a perfect bright, white screen. Amazingly, my unit does not show that blue tint screen at low PW light levels.

If that screen defect crept into the Amazon official photos, then it implies the screen defects are very widespread.

After seeing the Amazon official photos there, I'm convinced that level 22 for the PW light, which is the delivered default level CAN be used in all environments. However, that Amazon display resulted in my trying all PW light levels and I may vary it now in different environments to see which appears best for me. I may keep changing the light level each time I open the cover and use a variety of light levels.

xendula · 10-12-2012, 11:06 AM

Sirmaru, I just turned my PW up to 24. I use a rainbow on my screen: pink top, green middle with pink edges, pink bottom.

And no, "I" cannot read in bed in the dark with a brightness level of 22 or 24, because the book is really close to my face and the light blinds me.

Also, those pictures you just linked to only now appeared on their site, probably BECAUSE of all the returns and negative reviews.

sirmaru · 10-12-2012, 11:19 AM

Quote:

Originally Posted by xendula

Also, those pictures you just linked to only now appeared on their site, probably BECAUSE of all the returns and negative reviews.

Amazon motivation for showing the blue tint on the low PW light level in a dark room may have been displayed to convince folks with a similar tint at low PW light levels to simply keep their units since they are "defined as normal" now.

xendula · 10-12-2012, 11:49 AM

Quote:

Originally Posted by sirmaru

Amazon motivation for showing the blue tint on the low PW light level in a dark room may have been displayed to convince folks with a similar tint at low PW light levels to simply keep their units since they are "defined as normal" now.

I agree, I also think that's why they did it.

sirmaru · 10-14-2012, 09:30 AM

By the way, I had to do my first regular recharge after 7 days for the Paperwhite. The meter had gone almost to zero. There was no 15% signal given like on the K3 and Fire 1st Gen.

The only difference in the PW was the light dropped suddenly to zero. That must be the recharge signal.

10-10-2012, 08:03 AM	#21
sirmaru Wizard Posts: 2,426 Karma: 6561538 Join Date: Nov 2007 Device: Kindle PW 2013, HDX 2013, Galaxy S5 2014	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.

10-12-2012, 11:06 AM	#25
xendula eBookworm Posts: 2,300 Karma: 4525746 Join Date: Aug 2005 Location: East Coast brrrrr Device: Kindle 4B/K ~ Nexus 7 ~ Kindle Paperwhite 1&2 ~ iPad Air	Sirmaru, I just turned my PW up to 24. I use a rainbow on my screen: pink top, green middle with pink edges, pink bottom. And no, "I" cannot read in bed in the dark with a brightness level of 22 or 24, because the book is really close to my face and the light blinds me. Also, those pictures you just linked to only now appeared on their site, probably BECAUSE of all the returns and negative reviews. Last edited by xendula; 10-12-2012 at 11:09 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Lifespan of the Kindle	S Livingston	Amazon Kindle	83	01-01-2012 03:07 PM
Compact Fluorescent Bulbs -- some are unreliable	thibaulthalpern	Lounge	65	06-09-2009 01:40 PM
E-ink screen lifespan?	301verbs	News	21	05-22-2009 11:54 AM
Kindle battery lifespan?	gueeds	Amazon Kindle	75	02-27-2009 11:26 AM
Reader Lifespan (Longevity)	bob_ninja	Sony Reader	63	01-02-2007 11:59 PM

10-09-2012, 11:49 AM	#18
murraypaul Interested Bystander Posts: 3,725 Karma: 19728152 Join Date: Jun 2008 Device: Note 4, Kobo One	I suspect they must use a measurable amount, otherwise Amazon would advertise battery life figures with the light on full, rather than at setting 10 as they do now.

10-12-2012, 07:18 AM	#22
haydnfan Guru Posts: 649 Karma: 5632362 Join Date: Dec 2011 Device: Kindle PW 4, Oasis 2	It's not about being stubborn sirmaru, you are just flat out wrong. Raising the light level makes the defects obvious, they are not obvious at lower settings. And that is NOT why we use a lower setting. Some people don't want eye strain from bright light, else we would all use a tablet for reading. Now you don't get eyestrain from reading on a tablet, fine my parents are the same way but I do and many other posters do. I also have decent battery life, I think that the problem with the other PW owners and battery life is related to indexing and not the light.

10-12-2012, 08:21 AM	#23
xendula eBookworm Posts: 2,300 Karma: 4525746 Join Date: Aug 2005 Location: East Coast brrrrr Device: Kindle 4B/K ~ Nexus 7 ~ Kindle Paperwhite 1&2 ~ iPad Air	What haydnfan said. Plus, simaru, you don't read in the dark at all, so naturally, if you sit in a well lit room, or read during the day by the window, you are able to use a higher light setting. Not everybody has the luxury of reading time during the day, you surely can see that, no? Many users here read in the dark in bed (crazy idea... I know....) often with someone sleeping next to them. The PW was not made for daytime only use. Amazon built lower light settings into it for use in the dark.

10-14-2012, 09:30 AM	#28
sirmaru Wizard Posts: 2,426 Karma: 6561538 Join Date: Nov 2007 Device: Kindle PW 2013, HDX 2013, Galaxy S5 2014	By the way, I had to do my first regular recharge after 7 days for the Paperwhite. The meter had gone almost to zero. There was no 15% signal given like on the K3 and Fire 1st Gen. The only difference in the PW was the light dropped suddenly to zero. That must be the recharge signal.