Kindle battery life question from a first time user

DesiLinguist · 06-12-2009, 12:12 PM

Hi Guys,

I got my brand new Kindle DX yesterday and spent a lot of time reading various things including Manga PDF files etc. (actual time spent reading: ~8 hours). I noticed at the end of the day that the battery was already at 80% charge (20% used). Wireless was off for most of the day other than for a few minutes a couple of times to download content from the store.

So, does this mean that the battery life that Amazon claims (4 days with wireless on, 2 weeks with wireless off) is standby time and not just reading time? Can people provide estimates of actual reading time with wireless off? I ask because I want to make sure I have a realistic picture of the battery's capability before deciding whether my DX's behavior is below par or at par with others out there.

Since the battery is the same as K2, even K2 users are encouraged to provide their helpful input.

Thanks everyone!

jswinden · 06-12-2009, 12:52 PM

I cannot speak for the Kindle DX, but I've had three Kindle 2's and none of them have had the advertised battery life--not even close! If Whispernet is on, the batteries will drain in less than a day, at least on my three K2s. With Whispernet off, the batteries drain in about 20 hours of use. My Sony PRS-505 battery, on the hand, lasts for weeks.

emellaich · 06-12-2009, 03:09 PM

Another thing to be aware of ... in theory the K2 charges when its plugged into your PC. That doesn't happen in my case. In fact, I suspect it runs at full-on mode given the way that it depletes the battery.

It could be an issue with my K2 (comments anyone?); however, I believe its an issue with my Dell laptop. I have read in the past comments that some USB ports do not have all the juice that they should have to operate as power sources. I believe that this is probably the case with my laptop. Therefore, I think that it would charge if I hooked it to a different (desktop) computer with better USB ports.

The result however, was that when I first got it, and I was hooked up to my laptop for a while getting files transferred over, I thought I had a battery problem. Once I got it off my laptop into standalone mode the battery life greatly improved.

susan_cassidy · 06-12-2009, 03:15 PM

New books require indexing, which eats up battery power, also. It is best not to compare battery life after putting new books on the Kindle with just reading. And, of course, the Whispernet sucks the battery power down pretty rapidly, especially compared to just reading.

weatherman · 06-12-2009, 04:03 PM

With the wireless off, I generally get a couple of weeks of use out of my Kindle 2, reading it for about an hour to an hour and a half every day. Keep in mind that the power usage is by the page turn, not by the hour or week though. So when you're reading manga, which generally has a shorter read-time per page (I'd guess) than a page full of text, you're going to be "turning" the page a lot more and using more juice.

I don't for sure, but the fact that it's in PDF format might make a difference too, since it might take more processing power to display that rather than just text. I've certainly noticed that it takes longer to refresh pages with pictures on them on my K2 than ones without pictures, which means that some sort of processing is going on and not all pixels are the same.

So I guess what I'm really saying is that the Kindle's estimated battery life is probably accurate, but only in certain circumstances such as reading a book of plain text from end-to-end. Throw in PDFs and pictures and it's going to vary by use.

DesiLinguist · 06-12-2009, 04:28 PM

I think weatherman hit the nail on the head. It all depends on page turns, of course and the manga I was reading did lead me to turn pages a lot more often and on top of that it was in PDF and each page is a picture: the whole battery-draining trifecta!

I did notice that my kindle charged when I connected it to my iMac so that's good. Another strange thing I noticed is that the battery icon changed when I changed the text size. So, I went from size "3" (the middle of the 5 available sizes) to size "2" (one size smaller) and the battery icon now shows more juice available. Of course, this could just be a glitch in the battery refresh or it could be that the Kindle shows available battery life according to the size of the text: smaller text means fewer page turns which means larger battery life available?

weatherman, you said ... about 1.5 hours each day for a couple of weeks. So, that's about 20-24 hours of reading time which makes sense with that I have been seeing. I read a lot more than 1.5 hours each day and so it makes sense that my battery would be used up more each day.

Thanks everyone! It's good to hear that my Kindle DX is most likely not defective and that I won't have to send it back. I love it!!!

sirbruce · 06-12-2009, 05:09 PM

Quote:

Originally Posted by DesiLinguist

So, does this mean that the battery life that Amazon claims (4 days with wireless on, 2 weeks with wireless off) is standby time and not just reading time? Can people provide estimates of actual reading time with wireless off?

That's standby time, and not typical... more likely is 2 days with wireless on and 1 week with wireless on.

As for actual reading time, it depends on a couple of factors. Power is primarily consumer when actually turning pages, so translating page-turns into hours depends on:

1. How quickly you read (obviously).

2. The font size and line spacing you choose; more text on a page means fewer page turns for the same amount of text, thus longer battery life.

3. The type of material you're reading; pictures and charts typically go by faster than words.

That being said, you could expect between 15 and 45 hours of reading on the K2. The DX is probably about the same; bigger screen means more power per page turn, but more text per page, so it should even out. No idea yet if reading PDFs specifically consumes more battery power or not.

Your experience of 8 hours reading on 20% charge is not unusual; that would suggest 40 hours reading total.

sirbruce · 06-12-2009, 05:11 PM

Quote:

Originally Posted by DesiLinguist

I did notice that my kindle charged when I connected it to my iMac so that's good. Another strange thing I noticed is that the battery icon changed when I changed the text size. So, I went from size "3" (the middle of the 5 available sizes) to size "2" (one size smaller) and the battery icon now shows more juice available.

Are you sure you're looking that the amount the battery icon is filled, and not counting the wireless signal bars next to it?

DesiLinguist · 06-14-2009, 08:48 PM

Quote:

Originally Posted by sirbruce

Are you sure you're looking that the amount the battery icon is filled, and not counting the wireless signal bars next to it?

Yup, pretty sure that I was looking at the battery icon.

06-12-2009, 12:12 PM	#1
DesiLinguist Computational Linguist Posts: 110 Karma: 100 Join Date: Feb 2009 Device: iLiad BE, iPhone, Kindle DX	Kindle battery life question from a first time user Hi Guys, I got my brand new Kindle DX yesterday and spent a lot of time reading various things including Manga PDF files etc. (actual time spent reading: ~8 hours). I noticed at the end of the day that the battery was already at 80% charge (20% used). Wireless was off for most of the day other than for a few minutes a couple of times to download content from the store. So, does this mean that the battery life that Amazon claims (4 days with wireless on, 2 weeks with wireless off) is standby time and not just reading time? Can people provide estimates of actual reading time with wireless off? I ask because I want to make sure I have a realistic picture of the battery's capability before deciding whether my DX's behavior is below par or at par with others out there. Since the battery is the same as K2, even K2 users are encouraged to provide their helpful input. Thanks everyone! Last edited by DesiLinguist; 06-12-2009 at 12:31 PM.

06-12-2009, 04:03 PM	#5
weatherman Addict Posts: 385 Karma: 1010052 Join Date: Apr 2008 Device: (previous: Kindle 2, Kindle Fire) Kindle 4 WiFi, K3K, KPW	With the wireless off, I generally get a couple of weeks of use out of my Kindle 2, reading it for about an hour to an hour and a half every day. Keep in mind that the power usage is by the page turn, not by the hour or week though. So when you're reading manga, which generally has a shorter read-time per page (I'd guess) than a page full of text, you're going to be "turning" the page a lot more and using more juice. I don't for sure, but the fact that it's in PDF format might make a difference too, since it might take more processing power to display that rather than just text. I've certainly noticed that it takes longer to refresh pages with pictures on them on my K2 than ones without pictures, which means that some sort of processing is going on and not all pixels are the same. So I guess what I'm really saying is that the Kindle's estimated battery life is probably accurate, but only in certain circumstances such as reading a book of plain text from end-to-end. Throw in PDFs and pictures and it's going to vary by use. Last edited by weatherman; 06-12-2009 at 04:06 PM.

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06-12-2009, 12:52 PM	#2
jswinden Nameless Being	I cannot speak for the Kindle DX, but I've had three Kindle 2's and none of them have had the advertised battery life--not even close! If Whispernet is on, the batteries will drain in less than a day, at least on my three K2s. With Whispernet off, the batteries drain in about 20 hours of use. My Sony PRS-505 battery, on the hand, lasts for weeks.

06-12-2009, 03:09 PM	#3
emellaich Wizard Posts: 1,101 Karma: 4388403 Join Date: Oct 2007 Device: Palm>Ebookman>IPaq>Axim>Cybook>Kndl2>IPAD>Kndl3SO>Voyager>Oasis	Another thing to be aware of ... in theory the K2 charges when its plugged into your PC. That doesn't happen in my case. In fact, I suspect it runs at full-on mode given the way that it depletes the battery. It could be an issue with my K2 (comments anyone?); however, I believe its an issue with my Dell laptop. I have read in the past comments that some USB ports do not have all the juice that they should have to operate as power sources. I believe that this is probably the case with my laptop. Therefore, I think that it would charge if I hooked it to a different (desktop) computer with better USB ports. The result however, was that when I first got it, and I was hooked up to my laptop for a while getting files transferred over, I thought I had a battery problem. Once I got it off my laptop into standalone mode the battery life greatly improved.

06-12-2009, 03:15 PM	#4
susan_cassidy Wizard Posts: 2,251 Karma: 3720310 Join Date: Jan 2009 Location: USA Device: Kindle, iPad (not used much for reading)	New books require indexing, which eats up battery power, also. It is best not to compare battery life after putting new books on the Kindle with just reading. And, of course, the Whispernet sucks the battery power down pretty rapidly, especially compared to just reading.

06-12-2009, 04:28 PM	#6
DesiLinguist Computational Linguist Posts: 110 Karma: 100 Join Date: Feb 2009 Device: iLiad BE, iPhone, Kindle DX	I think weatherman hit the nail on the head. It all depends on page turns, of course and the manga I was reading did lead me to turn pages a lot more often and on top of that it was in PDF and each page is a picture: the whole battery-draining trifecta! I did notice that my kindle charged when I connected it to my iMac so that's good. Another strange thing I noticed is that the battery icon changed when I changed the text size. So, I went from size "3" (the middle of the 5 available sizes) to size "2" (one size smaller) and the battery icon now shows more juice available. Of course, this could just be a glitch in the battery refresh or it could be that the Kindle shows available battery life according to the size of the text: smaller text means fewer page turns which means larger battery life available? weatherman, you said ... about 1.5 hours each day for a couple of weeks. So, that's about 20-24 hours of reading time which makes sense with that I have been seeing. I read a lot more than 1.5 hours each day and so it makes sense that my battery would be used up more each day. Thanks everyone! It's good to hear that my Kindle DX is most likely not defective and that I won't have to send it back. I love it!!!

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