PRS-650 Battery Life

mediax · 01-04-2011, 08:16 AM

I bought a PRS-650 early in December, and am wondering if I've got a problem with the battery. Over the past two weeks I've read a couple of books (for a total of maybe 1,500 page refreshes) but the reader has drained from full to empty 3 times. I would probably have charged my 505 once in a similar period.

I'm wondering if this is just a new battery settling in, or whether it's a more serious problem.

My library is stored on a 2 Gb SD card, which is permanently in the reader; I put the reader into sleep mode, rather than switching it off; I charge the reader with the charger for my HTC HD2 phone, which seems to work perfectly well.

Bald Eagle · 01-04-2011, 09:10 AM

If you put your reader to sleep mode you get about 2 weeks per battery load, somewhat less if you actually do turn pages.
The SD card might put additional strain on your battery.

mediax · 01-04-2011, 12:05 PM

I know that the SD card causes an extra drain on the battery, so allowing for the reading I've done it sounds like I might not have a problem.

I never paid too much attention to the battery life on my 505, but it feels like I'm spending half my life worrying about charging the 650! Maybe I should just relax and read

That's only going to make things worse though, isn't it?

SeaBookGuy · 01-04-2011, 12:22 PM

Quote:

Originally Posted by mediax

My library is stored on a 2 Gb SD card, which is permanently in the reader; I put the reader into sleep mode, rather than switching it off; I charge the reader with the charger for my HTC HD2 phone, which seems to work perfectly well.

I have all but a couple of my books on an SD card, and use sleep mode, and it's taken a few hundred page turns (and lots of browsing, transfer activity, etc.) just to get down to three bars!

grooks · 01-04-2011, 03:04 PM

To the OP, next time you charge your Reader leave it plugged in for at least 8 hours (even if the charge light turns off).

jlbfoot · 01-04-2011, 03:28 PM

Make sure the MP3 player is not running/playing in the background.

MaxLV · 01-05-2011, 02:43 AM

Quote:

Originally Posted by mediax

I know that the SD card causes an extra drain on the battery, so allowing for the reading I've done it sounds like I might not have a problem.

I never paid too much attention to the battery life on my 505, but it feels like I'm spending half my life worrying about charging the 650! Maybe I should just relax and read

That's only going to make things worse though, isn't it?

Why do you beleive the SD card puts an extrat drain on the battery. IME (and through google searching) I can find no 'evidence' that having an SD card (or memory stck) permanently in the reader causes the battery to 'drain' or discharge faster.

Just the opposite in fact:

More likely it's because you're putting it in standby rather than powering it off between reading sessions.

Battery usage: Shutdown or Standby...

With a 4GB SD card permanently installed, and all the books (currently 608) loaded on the SD card. None in main memory.

--------------------------------------------------------------------------
I have been recording the dates when I have charged my 650 since I got it in late September.

I have recharged it when the battery meter showed 2 bars or 50% charge used/remaining.

For the first three months I have been powering off the reader between reading sessions, for the lasy two weeks I have been putting it on standby between reading sessions.

Here are the dates it has been charged and the number of days between the charges:

Charge dates and days between charges:
Powering off/shut down reader between sessions.
(date format DD/MM/YYYY)

23/09/2010 - first charge, full charge overnight on date of purchase.
26/10/2010 - 34 days since last charge.
28/11/2010 - 34 days since last charge.
19/12/2010 - 21 days since last charge.

On standby between reading sessions.
31/12/2010 - 12 days since last charge.

Averaging 3 - 5 hours reading/usage per day.

So it would seem that the battery lasts longer between charges when powering off/shutting down between sessions rather than putting it in standby.

Over the lifetime of the ereader's lithium ion battery (3-4 years) the less it is charged the longer it should last. Lithium ion batteries usually have a 'lifetime' of 300 - 400 charges, so the less often it is charged the longer it should last ie 12 -14 charges a year (approx. monthly charges) with powering off the reader betweens sessions as opposed to fortnightly charge, 26 - 30 charges a year, when putting the ereader on standy between reading sessions.

I will be continuing to put it on standby for the rest of January to see what battery usage is like in standby mode.

https://www.mobileread.com/forums/sho...d.php?t=114061

mediax · 01-05-2011, 07:41 AM

Quote:

Originally Posted by grooks

To the OP, next time you charge your Reader leave it plugged in for at least 8 hours (even if the charge light turns off).

I've already given the reader an 18 hour charge and an overnight charge, which is why I was starting to get a little concerned. I'll keep giving it long charges and see if that helps.

mediax · 01-05-2011, 07:42 AM

Quote:

Originally Posted by jlbfoot

Make sure the MP3 player is not running/playing in the background.

I once had exactly that problem with my 505, so that's been checked!

mediax · 01-05-2011, 07:45 AM

Quote:

Originally Posted by MaxLV

Why do you beleive the SD card puts an extrat drain on the battery. IME (and through google searching) I can find no 'evidence' that having an SD card (or memory stck) permanently in the reader causes the battery to 'drain' or discharge faster.

A number of postings I've read (mainly on this forum) have given me the impression that using an SD card for storage and reading uses more current that using the reader's main memory. I claim no expertise in this area and this could well be wrong.

Quote:

Originally Posted by MaxLV

More likely it's because you're putting it in standby rather than powering it off between reading sessions.

Yes, I do use standby rather than powering off and I would expect that to be a factor. However, I did the same with my 505, so I'm comparing like with like in that sense.

mediax · 01-05-2011, 07:56 AM

Quote:

Originally Posted by SeaBookGuy

I have all but a couple of my books on an SD card, and use sleep mode, and it's taken a few hundred page turns (and lots of browsing, transfer activity, etc.) just to get down to three bars!

I think you may have hit on the answer!

What with XMas and the fun of playing with my new toy, I haven't done any library management since getting my 650 (I transferred my library by simply switching the SD card between devices). Typically I would connect my reader to my pc 2 or 3 times a week - during which time it would getting charged (to a greater or lesser extent). I suspect that will account for the difference I'm perceiving in battery life.

Thanks everyone for your thoughts and suggestions!

MaxLV · 01-05-2011, 11:04 PM

Quote:

Originally Posted by mediax

A number of postings I've read (mainly on this forum) have given me the impression that using an SD card for storage and reading uses more current that using the reader's main memory. I claim no expertise in this area and this could well be wrong.

Yes, I do use standby rather than powering off and I would expect that to be a factor. However, I did the same with my 505, so I'm comparing like with like in that sense.

SD cards dont require any sort of voltage from a battery when installed on an inactive device (like a reader being in standby mode or powered off) , but the reader may be 'scanning' the SD card every so often even in standby mode (to see if it's still present) which would cause a battery drain...

My 650 being used in standby mode uses/drains the battery a lot faster than in shut down/power off mode between reading sessions.

I Last charged it on 31/12/2010, and today the battery meter shows it's down to 3 bars after just 6 days normal reading for me. Standby mode drains the battery a lot quicker that shut down/power off between reading sessions.
That still works out better that Sony's claimed 14 days of reading, I should get up to 24 days reading before the battery is completely drained, but still not as good as the 34 days between charges I'm getting when I shut it down completely between reading sessions with 50% charge still remaining on the battery.

poyraz · 02-15-2011, 10:31 AM

MAXLv thank you for your elaborate experiment, it provides solid positive support for shutting the gadget down for a longer battery life. I also will shut the gadget down from now on.

elcreative · 02-15-2011, 11:08 AM

Just curious as to why this big effort and debate over charging... of course Standby uses more than power off... it's in the name but by definition using your figures for lifetime charges (which are the manufacturers'), it makes little difference in reality.

Lifetime 300-400 charges - say 30 charges/year and lowest total still gives 10 years of usage on standby which is longer than the estimated Li polymer life by a factor of 2-3 times... and how many users seriously expect to be using the same eReader over the next ten years, never mind chances of accidental damage. Power OFF and 12 charges a year could give up to 30 years but as the battery is only rated at 3-4 years

Also it should be noted that it is 300-400 charges and that actually means drop to 50% and then charge to 100% = half charge not a charge... with LiION and Polymer batteries, a charge is just that a charge and it can be incremental to total the 100% that equals a charge.

Personally I'd rather have the convenience of Standby and it works just fine... I have a 505 that's around 3.5 years old, it's only ever been switched off when installing PRS+ otherwise it's permanently on standby... I read for several hours a day (and I read fast so that equals several hundred pages/day), every day... charge around 7-10 days when battery drops to two bars... this is the same regime I've used since day one and no drop off in performance yet... I also use the same regime for all my Sony's and my wife's. If I was going away for months and not using any of them then I would ensure half charge (battery manufacturers' recommendation) and Power Off otherwise standby works superbly...

Quote:

Originally Posted by MaxLV

Battery usage: Shutdown or Standby...

Averaging 3 - 5 hours reading/usage per day.

So it would seem that the battery lasts longer between charges when powering off/shutting down between sessions rather than putting it in standby.

Over the lifetime of the ereader's lithium ion battery (3-4 years) the less it is charged the longer it should last. Lithium ion batteries usually have a 'lifetime' of 300 - 400 charges, so the less often it is charged the longer it should last ie 12 -14 charges a year (approx. monthly charges) with powering off the reader betweens sessions as opposed to fortnightly charge, 26 - 30 charges a year, when putting the ereader on standy between reading sessions.

sircastor · 02-15-2011, 05:59 PM

I get the impression that the 650 is a little more power hungry because of it's touch system. The IR sensors which are utilized in the touch screen consume more power than the page turn buttons or the old resistive touch screen. It might be worth some investigation.

FWIW, I've also noticed that my reader's (650) battery tends to go quick than my 505 did. But then again, maybe I'm just reading more.

01-04-2011, 08:16 AM	#1
mediax Readaholic Posts: 255 Karma: 1058454 Join Date: Jul 2009 Location: Swindon, UK Device: Sony PRS-T2 (previously 505 and 650)	Battery Life I bought a PRS-650 early in December, and am wondering if I've got a problem with the battery. Over the past two weeks I've read a couple of books (for a total of maybe 1,500 page refreshes) but the reader has drained from full to empty 3 times. I would probably have charged my 505 once in a similar period. I'm wondering if this is just a new battery settling in, or whether it's a more serious problem. My library is stored on a 2 Gb SD card, which is permanently in the reader; I put the reader into sleep mode, rather than switching it off; I charge the reader with the charger for my HTC HD2 phone, which seems to work perfectly well.

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01-04-2011, 09:10 AM	#2
Bald Eagle Connoisseur Posts: 79 Karma: 777105 Join Date: May 2009 Device: Kobo Aura H2O, Kobo Aura One, Kobo Forma	If you put your reader to sleep mode you get about 2 weeks per battery load, somewhat less if you actually do turn pages. The SD card might put additional strain on your battery.

01-04-2011, 12:05 PM	#3
mediax Readaholic Posts: 255 Karma: 1058454 Join Date: Jul 2009 Location: Swindon, UK Device: Sony PRS-T2 (previously 505 and 650)	I know that the SD card causes an extra drain on the battery, so allowing for the reading I've done it sounds like I might not have a problem. I never paid too much attention to the battery life on my 505, but it feels like I'm spending half my life worrying about charging the 650! Maybe I should just relax and read That's only going to make things worse though, isn't it?

01-04-2011, 03:04 PM	#5
grooks Wizard Posts: 1,326 Karma: 30250 Join Date: Feb 2008 Location: Fort Myers, FL Device: Pocketbook Era, Kobo Forma	To the OP, next time you charge your Reader leave it plugged in for at least 8 hours (even if the charge light turns off).

01-04-2011, 03:28 PM	#6
jlbfoot idiot Posts: 91 Karma: 16 Join Date: Nov 2008 Location: Grand Cayman Device: Sony 505, 300, and 650	Make sure the MP3 player is not running/playing in the background.

02-15-2011, 10:31 AM	#13
poyraz Junior Member Posts: 5 Karma: 10 Join Date: Dec 2010 Device: Hanlin V3, Sony Prs650	MAXLv thank you for your elaborate experiment, it provides solid positive support for shutting the gadget down for a longer battery life. I also will shut the gadget down from now on.

02-15-2011, 05:59 PM	#15
sircastor Reader Posts: 85 Karma: 6124 Join Date: Jul 2009 Device: PRS-505	I get the impression that the 650 is a little more power hungry because of it's touch system. The IR sensors which are utilized in the touch screen consume more power than the page turn buttons or the old resistive touch screen. It might be worth some investigation. FWIW, I've also noticed that my reader's (650) battery tends to go quick than my 505 did. But then again, maybe I'm just reading more.