Possible Airplane Mode Bug?

[bischost]

Does anyone else think there's a bug with airplane mode that causes a process to hang up and drain the battery faster?  My reasons for thinking this are twofold:

1)  I actually get better battery life with airplane mode off and wifi active.  In fact, in this mode, I get the quoted 2-3 days.

2)  The only time my nook has locked up when in sleep mode has happened with airplane mode 'on.'  This event also resulted in losing 35% of my battery charge overnight. 

Do you think that if airplane mode is 'on' and wifi is still 'active,' the nook is still trying to connect to a network via wifi, but is being blocked by the airplane mode, causing the battery drain?

Sorry if this has been suggested - I've been following the battery life posts pretty regularly, but it's possible that I missed it.

[espo56]

I experienced the same thing last night. I forgot to turn airport mode on and work up to find that my nook had not lost any power over night.

[lilio]

Hmmm, mine was off and I lost 25%.  You may have something here.

[nickels]

Do you mean airplane mode off with wifi manually disabled? With airplane mode off and wifi on my wife's nook drained pretty quickly..

[bischost]

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nickels wrote:

Do you mean airplane mode off with wifi manually disabled? With airplane mode off and wifi on my wife's nook drained pretty quickly..

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No, I mean airplane mode 'on' and wifi NOT manually disabled.  I'm wondering if the radio is still trying to search for a network, even though the port or whatever isn't active.  I will try doing airplane 'off' and wifi disabled tonight.

[icebike]

With a few WIFI network scanning tools, you will find that Airplane mode ON disables WiFi, just as the manual says it does.  There is no need to separately set wifi off.

[cmiller173]

I don't think there is any question the "airplane" mode disables all of the radios (wifi/cellular) onboard.  The questions is that with the radio disabled by "airplane" mode are there processes running in the systems that are blindly trying to make a connection even though the radio is off.

[bischost]

Thanks, cmiller, yes.

I think it's a possibility because of some of the data posted in the battery life thread, particularly from the individual that did the graphs.  Airplane mode 'off' is giving more or less expected results, while airplane mode 'on' isn't in the ballpark.  Battery loss during sleep mode is 1.5%/hr with airplane mode off vs. 0.5%/hr with it on.  I can buy that, I suppose.  However, when reading with it off, you get a 5%/hr rate of decay vs. 4.5%/hr with it on?  Only 0.5% difference?  That doesn't make sense to me. 

I have no idea what average reading times per day the powers that be are using to determine the 10 day battery life, but obviously a 4.5%/hr drain is REALLY high.  I'd expect the wifi/3G to be more than 0.5%/hr in battery life.  Something's got to be still trying to work in airplane mode.

Shrug.  I dunno.  No real data to support, just tossing it out there.

[icebike]

Quote:

Battery loss during sleep mode is 1.5%/hr with airplane mode off vs. 0.5%/hr with it on.  I can buy that, I suppose.  However, when reading with it off, you get a 5%/hr rate of decay vs. 4.5%/hr with it on?  Only 0.5% difference?  That doesn't make sense to me.

The differences there seem well with in the error of the (somewhat haphazard) data collection methodology.

You are quibbling over 1/2% to1% with a data collection method that can't possibly be accurate to within 20% given the differences in reading habbits, screen light-ups, distance to cell towers, building construction, strength of wifi router signals, reading time, page turns, and phases of the moon.

I've never actually seen the nook GO ONLINE while I was reading.  Only while sitting in the daily or checking for content or browsing the store.  So Reading may be as effective as turning airplane mode on.

[bischost]

I'm not quibbling, I'm just brainstorming.  I am questioning the 4.5%/hr drain while reading.  No, I haven't seen it actually go online, but I submit that a background process is hung up due to airplane mode.  I deal with software for a living, and have seen stranger things happen.  That theory is as good as any other that I've seen posited.  Not say that's THE reason, but it's a possibility.  Another possibility is that the eInk screen just consumes more power than initially though.  Another is that the battery just plain sucks.  

I'm probably not explaining myself fully due to a loss in translation between my brain and the keyboard.  Shrug.

[AdamSelene]

It can't be the eInk display.  The Kindle 2 uses the same display and gets more than 10x the battery life (in terms of reading time on a single charge).

Unless they're doing spurious updates, perhaps.  How often do they update the clock and icons?

[icebike]

I didn't mean quibbling in a negative (argumentative) sense, more in the sense of calling attention to (questioning, brainstroming) half a percent in a high measurment-error environment.

Its entirely possible they forgot something as simple as to set no-atime, which keeps the processor uawake, or they are checking the touch screen trying to sense a swipe too often, or trying to test the non-existant ambient brightness sensor to manage touch screen brightness. 

There is a LOT of tuning you could do, but you would expect android to come reasonably well tuned. The nookdev boys have not even addressed this are, and then their server crashed, so they haven't had time.

I know what a difference in battery life shutting off 3G and going on Edge alone makes for my iPhone, and I really question why this device needs to use 3G at all. Maybe they could reprogram the radio just too use edge.  (I know it never does use edge, because edge chatters on nearby speakers, and my nook sits next to my desktop speakers).

[Doc_R]

Irrespective of Airplane on/off, Wifi, etc. the battery life is abysmal!  I guess that I should have been a bit suspicious when one of the announced features of the nook was its replacable battery.  In an afternoon of reading, I can easily drain the power from 100% to less than 25% by doing nothing more than turning pages.  Standby is less relevant considering the power drain when reading.

[Carrieee]

Interesting...here's a kink to your theory. I noticed that my battery was drained while on the plane. I had 2 flights..total of 3 hours...and from start to land, my nook went from fully charged to almost dead.

My wi-fi was off, and i had it in airplane mode. My cell phone batteries do the same thing...they drain fast when I fly - on or off.

Until I fully recharged my nook, the message said it could not take me off airplane mode due to insufficient power. Now whoever said you could fly to Japan and read your nook the whole time was on crack, unless you plug it into your laptop as you read. Otherwise, the battery runs out too quickly while in the air.

What sucked this last time is that I didn't bring my charger since I only planned on reading it while in the airports..but now I can't do that on my return flight since it is dead. Otherwise, my battery life is OK.