# Battery question



## Guest (Dec 14, 2010)

Hello,

What kind of a battery does the K3 have in it?  Does anyone here let their battery drain almost completely before recharging it or do you recharge just whenever you feel like it?  The reason I ask is because I don't know whether to let my battery drain completely before I recharge or recharge anytime due to the memory effect on some batteries.  I'm sure the K3 has a more sophisticated battery, but I just wanted to make sure since all of you know you cannot replace the battery yourself on the K3.

Thanks!


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## Morf (Nov 18, 2010)

It's a Li-Ion Polymer battery. 3.7V 1750MAh 6.5WH, picture here http://bbs.everybattery.com.cn/thread-986-1-1.html

I'm not going to get drawn into all the discussions about how you should treat batteries (since everybody seems to have their own opinions) but my understanding is that there is no significant memory effect with Lithium Polymer.

Personally I just charge it up when I feel like it - if I get the cable out to sync something I'll charge at the same time, or charge it before I go away on a trip. I've never bothered about letting it get low.


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## sotto (Nov 29, 2010)

My experience is, after many years of having electronic devices with Li-Ion batteries, is that it's NOT good to let them completely discharge. This seems to hasten their deterioration. My cellphone manual for example says to not completely discharge the li-ion battery, but rather to charge it regularly to keep it at maximum capacity and prolong it's useful life. This matches my experience. Once you start letting those batteries get on very low charge, their capacity to hold a full charge starts suffering significantly.  Your mileage may vary, as always.


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## Kimble (Oct 29, 2010)

This is the place => http://batteryuniversity.com/


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## Fireheart223 (Oct 3, 2010)

sotto said:


> My experience is, after many years of having electronic devices with Li-Ion batteries, is that it's NOT good to let them completely discharge. This seems to hasten their deterioration. My cellphone manual for example says to not completely discharge the li-ion battery, but rather to charge it regularly to keep it at maximum capacity and prolong it's useful life. This matches my experience. Once you start letting those batteries get on very low charge, their capacity to hold a full charge starts suffering significantly. Your mileage may vary, as always.


My understanding on this is the same. Only nickel batteries have memory, which means you want to let those run all the way down before charging, but lithium batteries do not have memory, so charging on a still partially-charged battery is not harmful, but rather a good idea so that the battery doesn't have to work harder to charge back up, which it would if you let it run all the way or nearly all the way down. I like to charge batteries when they're around the halfway-charged point.


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## arshield (Nov 17, 2008)

Kindles should never be allowed to drain the whole way.  I have had to replace a kindle (it was under warranty) because for some reason Kindles do not just shut themselves off when they drain, but they keep draining until they are dead.  If the battery is kept completely dead for some period of time (some times just a day or two) it can permanently kill the battery.  So if you will not be using a kindle for a week or more, you should turn the kindle off, not just let it sleep.  

And in general not let it get below 20% charge.


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## Elk (Oct 4, 2010)

arshield said:


> If the battery is kept completely dead for some period of time (some times just a day or two) it can permanently kill the battery.


Lithium batteries have a low charge protection circuit. They turn themselves off if they get too low. This will happen only if the battery is fully discharged and left this way for some time. The circuit exists as the battery needs a certain level of charge to recharge - below this retained charge level the battery will not properly recharge. Thus it commits suicide to prevent this.

It is appropriate to fully discharge a Kindle battery periodically. Without an occasional full discharge the battery meter will become incorrect. It doesn't hurt or help the battery either way, but does make your life easier of the gauge is accurate.

I personally let battery operated devices discharge a bit before recharging only because the batteries have a limited number of recharge cycles they can handle. It isn't really something to think about as this is at least 1,000 charges (2.5+ years if you charge every day).


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## arshield (Nov 17, 2008)

I don't know if kindles do not have the circuit or what but I had a fried kindle from being left uncharged for two weeks and Amazon cs said it was a very common problem and they replaced the kindle for me. Lots of info about others having the problem as well.  So if you are going to discharge, then you need to charge immediately after you discharge.


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## Elk (Oct 4, 2010)

The protection circuits are in the battery itself.

Your story makes sense.  

The battery discharges until the device doesn't work.  Normally one recharges it at this point.

However if it gets to this stage and sits for a while, or if the user turns the device on and off trying to use it, the battery can discharge to the point where it is unsafe to charge it.  This is a function of the technology.  At this point the battery kills itself.


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## westvlane (Apr 19, 2010)

I found this replacement battery(http://item.taobao.com/item.htm?id=8778119383) rated at 1830mAh and sell at about USD26.00


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