Kindle 4NT battery drain

heeby · 07-13-2012, 04:52 PM

I have a Kindle 4NT that seems to have normal battery life in use (lasts close to a month when I read daily) but drains faster than it should when "off" and stored. Twice now I have pulled it from a bag after a month or so not being used with the battery dead. The device was "off" with the 7 second press both times, nothing indexing, wireless off. Battery was fully charged when I stored it.

Can anyone think of why this would drain like this? Even if it were somehow accidentally turned "on" by having the button pressed when the bag moved it would then go to sleep and still shouldn't drain so fast right?

A Touch I am borrowing has sat just as long and the battery barely changed from full.

Blossom · 07-14-2012, 01:40 AM

I would call that odd. Maybe try a factory reset first to see if it solves the problem. If not time to call for a replacement.

My K4 does not do that I get about two weeks charge with my usual reading habits.

heeby · 07-14-2012, 08:08 AM

To be clear when I use it there is no issue with battery life. 3 weeks plus. This issue is when I have turned it off and stored it for a month or so. I cannot think of why it would drain just sitting when it functions fine in use.

I will replace the battery myself before I will send it back and risk getting a green screen. But as it works when reading without excessive drain it makes me think it's not the battery itself.

geekmaster · 07-14-2012, 08:13 AM

Quote:

Originally Posted by heeby

To be clear when I use it there is no issue with battery life. 3 weeks plus. This issue is when I have turned it off and stored it for a month or so. I cannot think of why it would drain just sitting when it functions fine in use.

I will replace the battery myself before I will send it back and risk getting a green screen. But as it works when reading without excessive drain it makes me think it's not the battery itself.

Unless you turned it off ("mostly off") by holding the power button until the screen went all white, then it was just asleep, during which it can index books and periodically "phone home" if wireless was left on. That will eventually drain the battery.

Did you leave wireless on when you "turned off" your kindle?

geekmaster · 07-14-2012, 08:15 AM

Quote:

Originally Posted by heeby

To be clear when I use it there is no issue with battery life. 3 weeks plus. This issue is when I have turned it off and stored it for a month or so. I cannot think of why it would drain just sitting when it functions fine in use.

I will replace the battery myself before I will send it back and risk getting a green screen. But as it works when reading without excessive drain it makes me think it's not the battery itself.

Unless you turned it off ("mostly off") by holding the power button until the screen went all white, then it was just asleep, during which it can index books and periodically "phone home" if wireless was left on. That will eventually drain the battery.

Did you have wireless on when you "turned it off"?

Good luck with replacing the battery. It has a soft shell and is glued into the K4 with a much stronger glue than is used to glue on the back cover. Trying to remove the battery is likely to destroy it (perhaps starting a lithium fire). Not recommended.

What is a kindle "green screen"?

HarryT · 07-14-2012, 09:12 AM

All K4s are still under warranty. Why not contact Kindle CS and get it replaced?

heeby · 07-14-2012, 09:14 AM

Geekmaster did you read my original post?

Wireless off, nothing indexing, turned "off" with the seven second press.

In another post recently where I asked a tutorial on changing the battery was linked and it is possible.

Green screen is the poor quality greenish screen with low contrast that plagues a lot of Kindles due to crap quality control. I went through several before I got a beautiful screen.

HarryT · 07-14-2012, 09:16 AM

Quote:

Originally Posted by heeby

In another post recently where I asked a tutorial on changing the battery was linked and it is possible.

Changing the battery on the K3 or a Touch is easy. On the K4, though, it's firmly glued in, and it's pretty well impossible to replace.

heeby · 07-14-2012, 09:51 AM

Not according to RainingLemur's post and the linked video.

https://www.mobileread.com/forums/sho...d.php?t=184747

HarryT · 07-14-2012, 09:52 AM

Well, on your own head be it! Please do let us know the outcome.

geekmaster · 07-14-2012, 09:57 AM

Quote:

Originally Posted by heeby

Geekmaster did you read my original post?

Wireless off, nothing indexing, turned "off" with the seven second press.

In another post recently where I asked a tutorial on changing the battery was linked and it is possible.

Green screen is the poor quality greenish screen with low contrast that plagues a lot of Kindles due to crap quality control. I went through several before I got a beautiful screen.

I went back and read it again. I had to read it three times (slower each time) before I caught the "wireless off" part near the end. My mind is full of some new code I am working that must have distracted me. Sorry. Regarding indexing, it might decide to index again even while asleep, if a recent "phone home" had loaded some new unindexed content (such as a subscription).

I would love to read about how they changed the battery. When I tried lifting my battery it was stretching the battery wrapper almost to the point of tearing, but the glue did not budge. Perhaps they are using different glue now. Please provide a link to your K4 battery removal reference. Thanks.

EDIT: Nevermind. Found it: http://www.youtube.com/watch?v=JO1Tg2OsPjU

Hmm... There is no FREAKING way that MY battery would come out like that. I tried. Besides, after removing his battery you could see 5 scratches on the glue. He had already removed it before. In the video it was not even glued in (except for slight stickiness of the remaining glue). They want to make it look easier than it is to sell more battery replacements...

I suspect that they may have HEATED the battery the first time, enough to melt the glue (which may also damage the battery if it gets too hot). Also, some K4s may have more glue, or stronger glue.

heeby · 07-14-2012, 10:15 AM

Yeah the post I linked to above was a result of me asking if anyone had see a way to do it. The tear downs I saw before said it wouldn't work but I figured it would be a matter of time before someone figured out a way. I am not going to do it now but it's good to know it's an option even if potentially difficult. I worked to hard to get good quality screens to gamble on a refurb being clear enough.

I would like to figure out why my batteries drain faster when off and not being used than when in actual use. It's weird. I get normal life when reading regularly...but when stored for a month "off" as off can be it totally drains. They were sitting on a shelf for months before being sold and retained a partial charge..but stored like that in a suitcase they drain so fast?

Also my devices are unregistered and have had wifi off since I bought them so I can't imagine there is any phoning home going on.

geekmaster · 07-14-2012, 11:04 AM

It is normal for a fully charged lithium battery to self-discharge relatively quickly. For longest battery life and longer storage, they should be discharged to less than 70% (and preferably 40%) before storing them. This can be done in diagnostics, using the "shipping mode" diag. There is also a script that can do it for you. It takes awhile...

In fact, mission-critical batteries are NEVER charged more than 70%. This gives them a MUCH longer lifespan, but requires recharging more often during usage. Internally, they are the same as consumer batteries charged to 100% (for longer time between charges), but they are labelled and rated differently, requiring different charging methods.

heeby · 07-14-2012, 11:09 AM

Can I set that mode via the device through some commands? How do I enter the "diagnostics" screen?

geekmaster · 07-14-2012, 11:24 AM

Quote:

Originally Posted by heeby

Can I set that mode via the device through some commands? How do I enter the "diagnostics" screen?

Entering (and leaving) diagnostic mode requires a little knowledge to avoid problems.

WARNING! TECHNICAL DETAILS AHEAD!

Spoiler:

07-13-2012, 04:52 PM	#1
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	Kindle 4NT battery drain I have a Kindle 4NT that seems to have normal battery life in use (lasts close to a month when I read daily) but drains faster than it should when "off" and stored. Twice now I have pulled it from a bag after a month or so not being used with the battery dead. The device was "off" with the 7 second press both times, nothing indexing, wireless off. Battery was fully charged when I stored it. Can anyone think of why this would drain like this? Even if it were somehow accidentally turned "on" by having the button pressed when the bag moved it would then go to sleep and still shouldn't drain so fast right? A Touch I am borrowing has sat just as long and the battery barely changed from full. Last edited by heeby; 07-13-2012 at 05:00 PM.

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07-14-2012, 01:40 AM	#2
Blossom Treasure Seeker Posts: 18,708 Karma: 26026435 Join Date: Mar 2010 Device: Kobo HD Glo, Kindles, Kindle Fires, Andriod Devices	I would call that odd. Maybe try a factory reset first to see if it solves the problem. If not time to call for a replacement. My K4 does not do that I get about two weeks charge with my usual reading habits.

07-14-2012, 08:08 AM	#3
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	To be clear when I use it there is no issue with battery life. 3 weeks plus. This issue is when I have turned it off and stored it for a month or so. I cannot think of why it would drain just sitting when it functions fine in use. I will replace the battery myself before I will send it back and risk getting a green screen. But as it works when reading without excessive drain it makes me think it's not the battery itself.

07-14-2012, 09:12 AM	#6
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	All K4s are still under warranty. Why not contact Kindle CS and get it replaced?

07-14-2012, 09:14 AM	#7
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	Geekmaster did you read my original post? Wireless off, nothing indexing, turned "off" with the seven second press. In another post recently where I asked a tutorial on changing the battery was linked and it is possible. Green screen is the poor quality greenish screen with low contrast that plagues a lot of Kindles due to crap quality control. I went through several before I got a beautiful screen.

07-14-2012, 09:51 AM	#9
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	Not according to RainingLemur's post and the linked video. https://www.mobileread.com/forums/sho...d.php?t=184747

07-14-2012, 09:52 AM	#10
HarryT eBook Enthusiast Posts: 85,544 Karma: 93383043 Join Date: Nov 2006 Location: UK Device: Kindle Oasis 2, iPad Pro 10.5", iPhone 6	Well, on your own head be it! Please do let us know the outcome.

07-14-2012, 10:15 AM	#12
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	Yeah the post I linked to above was a result of me asking if anyone had see a way to do it. The tear downs I saw before said it wouldn't work but I figured it would be a matter of time before someone figured out a way. I am not going to do it now but it's good to know it's an option even if potentially difficult. I worked to hard to get good quality screens to gamble on a refurb being clear enough. I would like to figure out why my batteries drain faster when off and not being used than when in actual use. It's weird. I get normal life when reading regularly...but when stored for a month "off" as off can be it totally drains. They were sitting on a shelf for months before being sold and retained a partial charge..but stored like that in a suitcase they drain so fast? Also my devices are unregistered and have had wifi off since I bought them so I can't imagine there is any phoning home going on.

07-14-2012, 11:04 AM	#13
geekmaster Carpe diem, c'est la vie. Posts: 6,433 Karma: 10773668 Join Date: Nov 2011 Location: Multiverse 6627A Device: K1 to PW3	It is normal for a fully charged lithium battery to self-discharge relatively quickly. For longest battery life and longer storage, they should be discharged to less than 70% (and preferably 40%) before storing them. This can be done in diagnostics, using the "shipping mode" diag. There is also a script that can do it for you. It takes awhile... In fact, mission-critical batteries are NEVER charged more than 70%. This gives them a MUCH longer lifespan, but requires recharging more often during usage. Internally, they are the same as consumer batteries charged to 100% (for longer time between charges), but they are labelled and rated differently, requiring different charging methods.

07-14-2012, 11:09 AM	#14
heeby Connoisseur Posts: 77 Karma: 87976 Join Date: Mar 2012 Device: Kindle 4NT	Can I set that mode via the device through some commands? How do I enter the "diagnostics" screen?

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