Register Guidelines E-Books Search Today's Posts Mark Forums Read

Go Back   MobileRead Forums > E-Book Readers > Amazon Kindle > Kindle Developer's Corner

Notices

Reply
 
Thread Tools Search this Thread
Old 04-28-2012, 02:09 AM   #1
kimkindle
Junior Member
kimkindle began at the beginning.
 
Posts: 9
Karma: 10
Join Date: Feb 2012
Device: Kindle Keyboard
Kindle Keyboard - Battery issues

Hi folks,

I have a battery issue with my Kindle Keyboard:

> gasgauge-info -c
Thu Apr 26 18:05:06 2012 INFO:battery charge 32%

Uptime in between approx. 15min - no WLAN/WiFi; no music; no reading; nothing but
the regular screensaver

> gasgauge-info -c
Fri Apr 27 01:26:04 2012 INFO:battery charge 6%

So my question is, what happened to my battery during this +5h?
After reloading I checked the battery status again and found out, that it has only? 96% almost immediately after the LED turned from orange to green - is this normal?

Thanks for Your help

Kim
--
kimkindle is offline   Reply With Quote
Old 04-28-2012, 02:34 AM   #2
hawhill
Wizard
hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.hawhill ought to be getting tired of karma fortunes by now.
 
hawhill's Avatar
 
Posts: 1,379
Karma: 2155307
Join Date: Nov 2010
Location: Goettingen, Germany
Device: Kindle Paperwhite, Kobo Mini
Yep, I think it's normal. Maybe you have a running process consuming CPU, but I doubt it. I guess this is to be expected by batteries in use. And the info they deliver isn't always that exact. As for stopping charging at 96% - that's also normal. Switching to green as a UI feature while continuing to trickle-load is quite common, too.
hawhill is offline   Reply With Quote
Advert
Old 04-28-2012, 10:50 AM   #3
geekmaster
Carpe diem, c'est la vie.
geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.
 
geekmaster's Avatar
 
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
Actually, for maximum lifespan, LiPo batteries should be kept between 40% and 70% charge. But we want maximum time between charges, which is why we "abuse" them by "overcharging" them to more than 70%.
geekmaster is offline   Reply With Quote
Old 04-28-2012, 01:43 PM   #4
NiLuJe
BLAM!
NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.
 
NiLuJe's Avatar
 
Posts: 13,477
Karma: 26012492
Join Date: Jun 2010
Location: Paris, France
Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E
Yep, on the K3, the LED switches to green @ 95%.
NiLuJe is offline   Reply With Quote
Old 04-28-2012, 05:56 PM   #5
ChrisKaos
Enthusiast
ChrisKaos began at the beginning.
 
Posts: 36
Karma: 10
Join Date: Apr 2012
Device: Kindle Touch
Quote:
Originally Posted by geekmaster View Post
Actually, for maximum lifespan, LiPo batteries should be kept between 40% and 70% charge. But we want maximum time between charges, which is why we "abuse" them by "overcharging" them to more than 70%.
I'd like to see some evidence for this. It's true that LiPos should be kept stored at around those percentages, but so long as you're using them, then there's nothing wrong with fully charging them.

In fact, by charging them more frequently, you are damaging the cells. More frequent charging than is necessary can be harmful.
ChrisKaos is offline   Reply With Quote
Advert
Old 04-28-2012, 06:32 PM   #6
NiLuJe
BLAM!
NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.NiLuJe ought to be getting tired of karma fortunes by now.
 
NiLuJe's Avatar
 
Posts: 13,477
Karma: 26012492
Join Date: Jun 2010
Location: Paris, France
Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E
Also, keep in mind than from time to time, the framework likes to mess around with the index files, even if nothing's changed in the content, and the more books you have, the more CPU it'll eat. (That's kinda true as a whole too, since it'll churn a bit on the index file every time it wakes up from sleep, too).
NiLuJe is offline   Reply With Quote
Old 04-29-2012, 02:29 AM   #7
geekmaster
Carpe diem, c'est la vie.
geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.geekmaster ought to be getting tired of karma fortunes by now.
 
geekmaster's Avatar
 
Posts: 6,433
Karma: 10773668
Join Date: Nov 2011
Location: Multiverse 6627A
Device: K1 to PW3
Quote:
Originally Posted by ChrisKaos View Post
I'd like to see some evidence for this. It's true that LiPos should be kept stored at around those percentages, but so long as you're using them, then there's nothing wrong with fully charging them.

In fact, by charging them more frequently, you are damaging the cells. More frequent charging than is necessary can be harmful.
Actually, I meant LiOn, not LiPo, but even so, lithium battery lifespan is a complex subject. Every time you charge it you reduce its lifespace. Sitting new in its original box reduces its lifespan. Buying a spare lithium battery is not useful because when your first battery goes dead, the spare is nearly dead as well. Fast battery chargers (one hour or less) like the kindles use typically skip stage two of the lithium charge cycle and go ready (green LED) at 70% capacity. They may continue to trickle charge to full capacity, but this can reduce lifespan due to metallic lithium plating. Batteries rated for long life (military and medical applications) are specified with a lower operating (full charge) voltage for the same chemistry. The lower charge voltage increases the lifespan. But for consumer devices, it is more common to give a full topping charge to the higher specified voltage, and just let the battery have a shorter lifespan. This is why cellphone batteries have such a short lifespan (to make each charge last longer). You can read more about this from many different websites...


Last edited by geekmaster; 04-29-2012 at 02:32 AM.
geekmaster is offline   Reply With Quote
Reply

Tags
battery, charging, kindle keyboard, low battery

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Battery life in kindle keyboard an kindle non touch. ersott Amazon Kindle 24 10-30-2013 04:33 AM
Kindle Keyboard Battery Life fr0stbit3 Amazon Kindle 20 10-03-2011 04:12 AM
Battery issues since updating to 2.5.8 Kindle DX bokolobs Amazon Kindle 7 03-25-2011 05:48 PM
Kindle 3 - Battery Issues abhiroopb Amazon Kindle 16 10-28-2010 11:12 AM
Kindle 1 battery issues, freezing Sydney's Mom Amazon Kindle 0 12-15-2009 06:08 PM


All times are GMT -4. The time now is 08:53 AM.


MobileRead.com is a privately owned, operated and funded community.