# K3 Real Battery Usage - how many page turns?



## dmalovic (Dec 15, 2010)

Hi!

I tried to read all the battery related kindle posts here, but not very many deal with the K3 battery life. Some users report 30 days of battery, some only a few days, and Amazon even replaced some peoples Kindles on account of high battery usage.

I was checking my ;dumpmessages log file (do a find on 'volt') to see how the battery is behaving. There is also a "def:battinfo:cap" value that shows the capacity in %.

I have 20 already indexed books on the freshly rebooted (hard reset) K3 3G with WiFi OFF and a fully charged Kindle, and in the last days, my battery is down to 60% of capacity, with maybe 4-5 hours of daily reading and many page turns after 5 days?

I am hoping the battery meter is not linear, and that it looses capacity fast at 4.2V, but stabilizes around 3.7 volts to indeed make it possible for the battery to last for a month?! It boils down to a few questions:

1. How does your battery meter go through the life of the battery, linear or dropping fast to about 60% and staying there for a while before finally going down to zero?

2. Is there a way to know how many page turns one does, as that would be the best indication of real battery life, for the K3

3. How long do you wait through the battery low messages before you put the device on recharge?

4. Is there a way to properly form/calibrate the Kindle battery, so the batt meter shows the right capacity? I waited until 3%, which is 65mAh remaining capacity and 3.428V. The full battery is 4.2V and 1873mAh capacity.

Even though I am afraid my K3 might be blowing through the battery too fast, the logs show that it indeed goes through the whole capacity range OK, so I would suspect that people reporting 30 days of battery must not be turning the pages much?


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## Atunah (Nov 20, 2008)

Yeah, I am not even getting near 30 days, not even on the same planet on that. I have the 3G and I keep my wireless off all times, only a couple of minutes here and there to get stuff. I read a lot. I started to write down my locations to see about where I end up. I usually charge every 6 days and at that time I am at around 20-30%. Again, wireless is off. 

I read 4 books with a total of 21000 locations on that test. The books are pretty average in length. 

I tried looking at that log once before and its all gobbledegibble to me. I can't read nothing on it. I do recall reading the name of my router over and over and it was at a timestamp where wireless was turned off. So that confused me. 

I even tested with forgetting the wifi so it would only work with 3G. Still wireless on off. It took the same time to go down on battery. 

I remember I could barely read a whole book with my K1 before the battery went down so I guess I I don't have no complaints  . I have the 1 year warranty from Amazon and I also have Squaretrade, so if the battery does die on me down the road, I don't have to worry at least. 

Would be nice though to get more time out of it, but it is what it is. 

When people talk about how many days their Kindle lasts, it doesn't really help anyone else in reality. I read a lot of books, someone else might read one book in that week, or one book in 2 weeks. 

I never tried leaving on wireless to see how long it lasts. I notice that when I do have it on, battery goes down quickly. So I keep it off. 

I am on 3.02


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## Mike D. aka jmiked (Oct 28, 2008)

1.Seems to be fairly linear.
2. Not unless you manually keep track of it.
3. I have no pattern. I recharge when I feel like it, generally plug in at night every 10-14 days. think I've seen the low battery warning twice since I got my K3 in September.
4.No.

I have about 200 books on the K3. All seem to be properly indexed. I rarely have the WiFi toggled on.

The only device I have that meets the manufacturer’s charge life is my iPad, which does get the stated 10 hours on a charge. Everything else gets 50-75% of charge life. The K3 falls into this range, as did my K1 and k2.

Mike


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## Elk (Oct 4, 2010)

Anecdotally the battery meter appears linear.

As to number 4, as with all lithium batteries, the meter will be more accurate if you allow the battery to discharge completely on occasion and immediately recharge it.

Between 20-25 hours of use with a battery drain of 40% appears perfectly reasonable to me. Remember, Amazon states "lasts _up to_ one month with wireless off." This long period would be with light use, of course.

Let me be the first to note that I believe you are over thinking this just a little. 

Edit: Thinking about this further, 20-25 hours and only 40% drain is spectacular!

If battery drain is linear, this means a minimum of 50 hours use between charges. That is, 1 2/3 hours a day for 30 days before plugging it in.

And yes, I am now over thinking this as well.


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