Am I killing my battery? fully charged = 84%

[kzink1]

i haven't even used my nook yet, except to play around a little when i first got it and to download many free classics, but done no reading.  when i charged my nook, and the orange light went off, i knew it was then fully charged.  i turned it on without even unplugging the charge unit, and it says my battery is at 84%!!!!!!!  this is totally unacceptable.  what is going on?

[Doug_Pardee Distinguished Bibliophile]

kzink1: It takes a few discharge/recharge cycles for the battery-level indicator to calibrate itself to your battery. Your battery is fully charged, but the level indicator hasn't figured it out yet. It's not a problem, and will clear up very soon.

[Infinion]

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h2oskierc wrote:

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Infinion wrote:

-Snip- Lithium Ion based systems -mega snip

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Isn't the nook lithium polymer, or are the two the same?

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Apparently it is Li-poly.  The charge and discharge characteristics are similar.  I'm surprised by the complaints with the battery discharging too far or something similar from above.  Could possibly be a design flaw.  I'm not sure that's very likely though.  BUT, same for me, no first hand experience with that kind of thing, so I don't know.  Maybe someone at B&N's hardware engineer contractor would be so kind as to provide me with the schematic, then we'd know for sure.  No chance of that happening though. 

[Suyai]

I don't know if this will help or not but I completely discharge my nook's battery probably once a month and when it gets too low it has always switched to a low power mode- displays an image of the charging cable and will not allow you to turn it on or off (I've certainly fiddled with it and tried) until you've plugged in and recharged for a substantial period of time. I assume that it's a failsafe program for the nook to keep the battery from being depleted past the point of recharge, and would be concerned if it wasn't there.

My battery runs at least 10 hours if I'm primarily reading in airplane mode, and I haven't noticed any decrease in battery life between firmware updates.

[Cranky_Carl]

I would really like to get the 1,000 pages some commenters have mentioned.  With version 1.4 software, airplane mode ON, touchscreen set to 10 seconds and minimum brightness, I usually get around 500 - 750 page turns.  This translates to about 8 hours of reading for me, barely made it to Hawaii.  The upcoming trip to New Zealand will very likely exhaust the battery about 1/2 way through the flight. 

That is a far cry from the advertised battery life of 10 days!

Since tools that could be made into a "weapon" are not allowed in the plane cabin, changing the battery during the flight is not really an option.

Sure hoped that Customer Service would have some suggestions for me when I sent a rundown on my configuration to them, along with the battery life I have been experiencing.  All I got was a canned response with suggestions for improving the battery life, most of which were already configured as documented in my original message.  So much for Customer Service actually reading what was written.

[Infinion]

For anyone having various battery life problems, have you tried to do a full discharge before?  Even though some people say there have been reports of a full discharge completely disabling their nook, I'd say it's worth a try.  Run it until it's dead, preferably with the Wifi or 3G blasting at the same time; that would increase the current requirements.  Then let it sit for a day to add some self discharge.  Try to turn it on a few times and make sure it won't come on any more.  Then charge it all the way until the light goes off.  In fact, just leave it on all day or something similar. Maybe the software is causing the nook to turn off well before the end of the discharge curve because it is confused abuot how much capacity is left in the cells.

One of the systems I've designed and is in the field in high numbers uses very large lithium Ion packs.  A few customers sometimes complain that the battery life indicators (which happen to be mission critical in this case) always tell them the batteries are dead well before they actaully should be, or actaully cause the unit to die.  Because this system is crtitical to stay active for as long as possible, even without battery power, it is designed to completely discharge the batteries up to the point that the hardware protection on the packs lock them out to protect against under voltage problems on the cells themselves.  Other systems will automatically turn off or put to sleep the main systems that draw from the batteries so that the underlying elextronics can still run to maintain state of the world.  That would be controlled by some additional software that monitors the battery state and current requirements.   If the nook is confused about how much energy is remaining in the cells, it might turn itself off before it really needs to.  A discharge-charge cycles might help it get its bearings on the battery again.  Just a thought. 

[ABthree]

@Cranky_Carl

Welcome! 

With a transpacific flight in your future, consider picking up a New Trent Super-pack IMP500 external battery.  Several people, including me, on these boards have bought them for their Nooks, and are very happy with them.

The price is reasonable, they're very compact and unthreatening looking, and will keep your Nook well charged until you're back on the ground, and then some.

[Michael-V]

@Cranky_Carl,

Although it can become "trendy" for many to state they are receiving a canned response, I do want to clarify that some responses are stated by us in the same manner every time so as not to eliminate any necessary steps.

We can tell you different ways to say the same thing but that would serve no purpose other than to possibly add confusion to the right steps to take.

So allowing the battery to discharge and then fully charge from time to time will extend the overall length of the battery.  However, this won’t be noticed until after several charges.

[xamier]

Ummm, I occasionally get my battery low enough that I get a pop up telling me to recharge and that the battery will go a little longer if off Wi-Fi.  I plug in to charge at this point.

Am I getting the battery low enough to keep from shortening its “charging memory” (?) I don’t want to run the batter all of the way out and crash my nook, but I also want to optimize my battery life too.

Thank you.

[Ozman69]

I always charge mine when I get that warning too.  I don't let it get much past that before plugging it in.

[xamier]

What I am wondering is if charging when one gets the warning will keep the battery at the optimum charge?

[nekowafer]

Lithium Ion batteries do not develop a memory. The best way to use them would be to only let it get to around 20% or so, then charge. Letting it run down completely should only be done occasionally.

The battery only has a certain number of full discharges in its lifetime. Now, this is a large number, something in the thousands I'm guessing. But the less often you let it fully discharge (with the occasional full discharge to maintain it's 'health'), the longer you'll have the battery.

[Cranky_Carl]

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Michael-V wrote:

@Cranky_Carl,

Although it can become "trendy" for many to state they are receiving a canned response, I do want to clarify that some responses are stated by us in the same manner every time so as not to eliminate any necessary steps.

We can tell you different ways to say the same thing but that would serve no purpose other than to possibly add confusion to the right steps to take.

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I understand the need for consistency. 

My frustration leading to the "canned response" comment was born from the comparison of the information I provided in my initial query, and the response received, most of which instructed me to set my configurations to settings that were already documented to be in effect.

Many of the comments on this thread, and others, leads me to believe that the Nook advertising should provide a much more definitive "yardstick" of battery life, such as number of page turns.  The touted "up to 10 days" does not appear to include likely levels of use by a fast or heavy reader, which is exactly the market segment most likely to invest in the Nook.