When Do You Charge Your Kindle?

[JerryinOCMD]

Just wondering how low you let your Kindle 3's battery get before you re-charge it. Does it make any difference, as far a battery-life goes?

[rcuadro]

I charge it when it is almost drained. though most of the time when it is at about 1/3rd charge I just plug it in when I go to bed..

[HarryT]

I find that plugging it in to my PC every few days to transfer books, etc, is sufficient to keep it fully charged. I rarely see the battery meter shift from "full".

[gtriever]

I do not have a Kindle; however, it seems the recommended recharging level for Lithium-Polymer batteries is at about the 40% mark.

[HarryT]

Originally Posted by gtriever

I do not have a Kindle; however, it seems the recommended recharging level for Lithium-Polymer batteries is at about the 40% mark.

It's recommended that you charge the battery to about 40% if you're planning to store it, unused, for a long period of time. In regular use, however, it makes no difference to the life of lithium polymer batteries such as the Kindle uses whether you discharge and then recharge them, or top them up regularly.

[gtriever]

Actually, it does. At levels at or below 2.5VDC, the batteries can "die" and cannot be safely recharged. Most devices with Li-Poly batteries will have a protection circuit built in to prevent discharging at levels less than 2.7 - 3.0VDC. I'm assuming the Kindle has that circuit as well, so you're partially correct.

[OakIris]

I charge my Kindle whenever the battery icon shows that it is down about 20%; I have never waited until the battery low warning comes on to charge it. Just my preference!

The Kindle has a lithium polymer battery. Others here may disagree with me, and I am certainly no expert, but from what I have read, frequent, "shallow" charges are better than letting the battery discharge until it is almost empty. Here is a quote from an article about charging the lithium-polymer battery in a MacBook that I think applies to this type of battery in general:

Avoid full discharges unless calibrating.
Frequently draining the battery all the way or nearly all the way will put additional strain on the battery. With older NiMH battery technology this was common “must do” because of memory problems with the battery remembering where it was recharged from, reducing its capacity. Now, with a Lithium-Ion/Polymer battery, this isn’t the case. Its better for the battery to be partially discharged and recharged again than giving it a full discharge and bringing it back.

(The full article can be read at http://www.interrupt19.com/2008/03/3...ong-as-it-can/ )

Holly

[HarryT]

Originally Posted by gtriever

Actually, it does. At levels at or below 2.5VDC, the batteries can "die" and cannot be safely recharged. Most devices with Li-Poly batteries will have a protection circuit built in to prevent discharging at levels less than 2.7 - 3.0VDC. I'm assuming the Kindle has that circuit as well, so you're partially correct.

I'm well aware of that. I was referring to recharging from the state at which the Kindle gives a "low battery" warning.

[JeremyR]

Originally Posted by HarryT

I find that plugging it in to my PC every few days to transfer books, etc, is sufficient to keep it fully charged. I rarely see the battery meter shift from "full".

This is the case for me as well. Really quite nice...

[wvcherrybomb]

For some stupid reason I was under the impression that it was best to not charge until battery was completely dead. I would much rather charge it often and keep it full but always felt guilty about doing so.

I'm glad this subject came up. Now I know I can charge whenever I want even though my K3 seems to last forever on a charge. Even with using the lighted cover 90% of the time, I still get about 28 hours per charge.

[dengar]

I usually wait until around half.

[TallMomof2]

When I think of it! Maybe once a week.

[paperwastage]

when my K DX G complains of low battery and shuts off... about a week of intensive usage(>3 hours a day), 3g sometimes turned on...

[wolw]

Originally Posted by gtriever

Actually, it does. At levels at or below 2.5VDC, the batteries can "die" and cannot be safely recharged. Most devices with Li-Poly batteries will have a protection circuit built in to prevent discharging at levels less than 2.7 - 3.0VDC. I'm assuming the Kindle has that circuit as well, so you're partially correct.

2.7V under load (which the Kindle can't produce) was the norm four years ago, personally I wouldn't go below 3.0V. Below 2.7V under load will permanently damage your battery. 3.85V for long time storage.

Lithium Polymer batteries aren't affected by being loaded in a partially loaded state, but they do have a limited number of charging cycles before they start to degrade. If Amazon have done their homework it should warn around 3.1-3.2V.
Giving it a normal life cycle of ~500 ±150 charges it should last a while

Being a Electric Powered (EP) R/C model airplane pilot has its advantages

Peter

[bhartman36]

Originally Posted by HarryT

I find that plugging it in to my PC every few days to transfer books, etc, is sufficient to keep it fully charged. I rarely see the battery meter shift from "full".

This works for me with the K3 (wifi-only version), as well. With my K1, it was typical for me to get about a week, maybe a week and a half on a charge, but that might be because I bought my unit second-hand off of Ebay. With the K3, I've had it for > 2 months, and I don't think I've ever seen it go below 50% since my first week of using it (when I literally just left it on 24/7 with the wifi on and basically torture-tested it).