Quote:
Originally Posted by speakingtohe
What I cannot figure out is why Sny readers seem to poll the screen even in sleep mode when there is no action available by touching the screen. But something touching the screen when in sleep mode seems to eat up power.
While I cannot actually prove it I am pretty sure this is the case. When my 350 (no cover) sits on a table it's battery lasts for weeks if not used. When it is in a pocket in my backpack in three days it goes into shutdown with one bar remaining.
My T1 has a lighted cover which is flexible and it seems that the reader discharges faster when it is closed. Probably it is crossing the beams.
My 600 has a solid cover and acts the same whether the cover is open or closed.
Why are the beams still active in sleep mode and why does it discharge faster when they are crossed? Rhetorical question, but it annoys me that this seems to be the case.
Helen
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Interesting observations, but so far as I have seen, both my PRS-650 and PRS-T1 shut down the IR touch-screen scanning when in sleep mode (or rather, at least, this is the way that they are
intended to work).
I haven't seen it yet on my T1, but on my trusty PRS-650, like many others, I have seen one or two instances of dead-battery-in-a-single-day-during-sleep problems, which may be related to a software glitch preventing the sleep mode from fully shutting down everything.
This kind of glitch could indeed leave the touch-screen active, so who knows?
But even baring this kind of abnormal operation, even when the reader is working properly, there are a few things that can mimic the kind of behaviour you described.
First, are you really really really sure that you tapped the button and manually put the reader to sleep BEFORE closing the cover, or like me, did you figure that letting the reader shut itself down is just as good? (or
better because it saves wear and tear on the power switch).
Letting the reader shut down itself, rather than forcing it to do so manually, does indeed save wear and tear on the power switch, but if you close the cover before the reader puts itself to sleep, IT MAY NOT BE ABLE TO PUT ITSELF TO SLEEP DUE TO CONSTANT FALSE TOUCH SCREEN INTERRUPT ACTIVITY.
Another factor that can kill the battery in only a few hours while reading is if the reader has dust on the screen, or is used under lighting conditions that interfere with the infra-red touch screen scanning and cause false touch screen inturupts.
For example, setting the reader down on a desk near a bright Halogen light (which have a lot of IR mixed with the visible light emitted) could also create enough 'IR noise' to keep your reader from sleeping properly. I can't positively verify this based on official information in the manual, but it does make sense given how the touch screen scanning works, and anecdotally I can report that I have seen the reader loose half it's charge in only a few hours when set on a desk too close to a nearby light.
To avoid these kinds of issues, I am careful now to always either manually shut down the reader (or verify that it has gone to sleep itself), BEFORE closing the cover (or laying it open on a desk under a bright desk lamp) and, since making this change, haven't seen a single case of rapid-battery-discharge.