site Search:


 
    All Forums Hot Topics Gallery






how-to block ads


 
Search Topic:
Uniqs:
998
Share Topic
Posting?
Post a:
Post a:
Links: ·Forum Rules ·Electronics FAQ ·Parts! Where to Purchase Parts ·Electronic Circuits
AuthorAll Replies

pulsar777

join:2009-12-21

Amazon Kindle 4 battery

Amazon Kindle 4, how long the device can be stored with empty battery? I just bought device about 6 monts ago, just checked it, the initial battery charge was about 1/3. Then I have not used it for 6 months. Today I just turned it on, it showed an empty battery sign, cann't even be turned on. I full charged it in 3 hours.
Is it safe for battery stay empty for longer period, about 6 month? Or it already been damaged?

lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
Reviews:
·TekSavvy DSL

said by pulsar777:

Is it safe for battery stay empty for longer period, about 6 month? Or it already been damaged?

Well, I found my old Nokia cellphone which was sitting in a drawer for 2 years and managed to charge it up completely.

I think these lithium-ion batteries stop supplying current to the phone/tablet circuit when voltage drops below a threshold.

TheMG
Premium
join:2007-09-04
Canada
kudos:1

reply to pulsar777
Try not to do that too often. Best is to try to keep the battery at about 25-50% charge while the device is not being used for long periods of time.


pulsar777

join:2009-12-21

In my case, the initial battery charge was about 25-30%. And during the 6 months I haven't used the Kindle, the battery self-discharged almost completely. I know the battery self-discharges does decrease the overall shelf-life of battery.


lutful
... of ideas
Premium
join:2005-06-16
Ottawa, ON
Reviews:
·TekSavvy DSL

said by pulsar777:

In my case, the initial battery charge was about 25-30%. And during the 6 months I haven't used the Kindle, the battery self-discharged almost completely.

You could recharge that Kindle every 6 months to about 40-50% state of charge if you are not using it.

Use ball-park 5% per month discharge rate for modern Li-ion battery modules. The built-in protection circuit accounts for about 3% while the battery itself discharges at a rate proportional to state of charge and temperature.

But it will charge up even when fully discharged for minimum X cycles specified by battery manufacturer. X could be 100-500.

pulsar777

join:2009-12-21

does the Kindle 4 have built-in protection circuit?


TheMG
Premium
join:2007-09-04
Canada
kudos:1

said by pulsar777:

does the Kindle 4 have built-in protection circuit?

More than likely yes. Manufacturers have learned their lesson and have figured out that Li-Ion cells can be quite hazardous without adequate protection.


Subaru
1-3-2-4
Premium
join:2001-05-31
Greenwich, CT

reply to pulsar777
My kindle when it does run out it takes maybe 10 min of charging before it has enough power to turn on then it does the booting with the Kindle tree logo and it fully charges in about a hour or so.

I try and remember to turn off the 3G because it will kill the battery in a matter of days.



SmokChsr
Who let the magic smoke out?
Premium
join:2006-03-17
Saint Augustine, FL

reply to pulsar777
I don't know about the Kindle specifically, but as you describe it, the Kindle is the same as most. Which is the battery circuit is cut off completely below a certain point. Up until then the battery is still connected to the device which is still drawing a very minimal amount of current, mostly just enough to keep the turn on circuit active.

While it's not good to let the device remain in cut off mode for an extended period of time, in this case it would appear that you did recharge it prior to any damage to the battery occurring.

If the Li-ion battery gets too low it will not want to recharge at all.


Friday, 24-May 12:58:40 Terms of Use & Privacy | feedback | contact | Hosting by nac.net - DSL,Hosting & Co-lo
over 13.5 years online © 1999-2013 dslreports.com.
Most commented news this week
Hot Topics