PRS-T1 battery life - in time rather than page-turns?

[mwerle]

Hi,

I'm just considering getting my first eReader (I'm sick of reading off my mobile phone screen..) and am slightly confused - the battery life for the PRS-T1 is quoted as 3 weeks to a month (if reading 30min/day).

I've looked at eReaders on and off for a couple of years ago now, and battery life was always quoted in number of page turns.  Apart from readability, I was under the impression that the major bonus of e-Ink compared to traditional LCD/OLED displays is that it doesn't use any power unless the page is refreshed - is this no longer the case?

I realise that the T1 has WiFi, but surely that can be turned off.  So what gives?

Thanks,

- Micha.

Message was edited by: mwerle

Message was edited by: mwerle

[Drumzman]

Hi Micha,

I think you've hit the nail on the head when you mention that this new model has Wi-Fi (unlike any previous models).  My guess would be that if you turned the Wi-Fi off completely then you'd get battery life very similar to the previous models, where as you mention they only really consume power when you refresh the page.

I suppose that as this model will have Wi-Fi, when it comes to quoting battery life there has to be an assumption that the feature will be used at least some of the time.  Wi-Fi certainly would consume more power, so I guess that battery life has to be quoted based on a kind of typical average use:smileyconfused:.

I wouldn't be surprised if there wasn't some kind of 'standard' that has to be followed by all manufacturers when they quote battery life based on usage/features.

Ultimately it all boils down to how you personally want to use the device, and if that's without using the Wi-Fi functionality then you'd maximise the battery life similar to previous Readers.  I'm second guessing a bit here as the new model isn't out yet, but I hope my reasoning makes sense!:smileyhappy:

[mwerle]

Hi Drumzman,

Actually, looking at the spec  sheet, the battery life is always given in time, rather than page-turns,  even when wifi is turned off:

Battery Life (*2) (reading EPUB eBooks)  
Approximately over 1 month (wireless off), Approximately up to 3 weeks (wireless on)

(*2)
Reading approx 30 min each day. In low coverage areas,  wireless usage will consume more battery. Actual battery life may vary  upon your wireless usage, settings, battery and environmental  conditions.

I  was wondering whether it was because of the touch-screen, which uses IR  sensors which must presumably be continuously powered on.  The PRS-650  -used- to be advertised in number of page turns, but that is also no  longer the case!  The current product sheet:

Battery Life (reading EPUB eBooks)
2 full weeks of reading

And this post (http://www.mobileread.com/forums/showthread.php?t=97839) confirms what I remember:

In the 650 user manual we have this:
 
 "Maximum Battery: Approx. 10,000 continuous page turns
 when reading only.

There's  also other threads on that forum where it is discussed that the newer  Sony eReaders with touchscreens seem to continuously drain power with  people recommending they have to be completely powered down when not  reading.  This is NOT what I expect from an eBook reader!  While I will  mostly be able to charge it regularly, a large part of the attraction of  an eReader for me was the capability for an extended trip away from the  grid.

Very disappointed that eReader technology appears to  be regressing.  Apart from readability, the whole point of eInk was the  fact that there were no power requirements to maintain the display -  only to change the display.  Heck, even my ancient Palm Pilot could run  for a month on a single charge, with daily use! And yes, I used to read eBooks on that as well as use it as a PDA.

Cheers,

- Micha.

[carpetmojo]

No no no....

Current best practice with the PRS X50's, from advice regarding the battery technology they use, is. in short, you can cause harm and diminished battery life/power by a) not charging up when low  ( when on two bar is recommended) and b) you will not do any harm by "over-charging" ie overnight.

In addition, it is best not to power down completely, except when not to be used for a longish time - I think 5 days is about it, but not sure.

Since I learnt this lot, I've kept in "on" all the time over 8 months, in sleep mode overnight, and for a couple of days when not in use, and the battery charge now lasts noticeably longer than before.

Apparently the real no-no is letting them run right down, it damages the battery's ability to hold a charge, and its' memory - whatever that is !

I suggest you visit MobileRead forums - they have tech-geeks there that leap on things like this with delight, and often work with the things themselves. The search facility ids excellent .

And it's good for all sorts of ereading stuff generally.

Hope this is of help/interest.

[mwerle]

Thanks for your reply carpetmojo, your advise on battery handling is useful although I had read most of that on the MobileRead forum already, and it's not quite on topic of the question I'm trying to get answered..  which is about the change in the way battery life is being advertised for newer model eReaders and the fact that they appear to behave more like traditional electronic devices now (constant battery drain) rather than like the first generations of eInk devices (battery drain only on display update).

Also.. what did the 'no no no' refer to?

Thanks,

- Micha.

Message was edited by: mwerle

Message was edited by: mwerle

[carpetmojo · Accepted solution]

Hi mwerle, The no no no referred to the powering down policy, and I'm sorry, didn't spot the link main heading for MobileRead.

Not much point going on really - you've read what I have !

Did you catch the Mountie's offering, which sort of kicked the discussion off early on there a good few months ago ? He was very knowledgeable, and knew his batteries, so to speak !

Understandable, too...............

This is the great thing about forums, you get a lot of info from a lot of sources, and each kind of helps each other, and if the answer doesn't pop up here, MobileRead usually does.

But, I have to say, I think strides are definitely being taken by Sony support. I think the T-1 is a re-launch of the Sony reader presence, and early signs seem to show a very favourable reaction. And the pricing policy puts it smack in the face of the kindle, Kobe, Nook, etc... and the support system should reflect those of these rivals.

Message was edited by: carpetmojo

Message was edited by: carpetmojo