Gen3 Any reason to switch off

[romi]

Hi everyone,

I set mine to 1 hour, after which it automatically switches off, and by default Bookeen sets it to less than that.

Anyone know of a reason why it'd be better to let it sleep than to leave it on?
I could pick up reading from where I left off faster.

Possibilities:
- strain on the display, even if minimal
- battery life (although very small difference I suppose as the display does not affect it, only keeping the book in memory)

Thanks for your input,

Roman

[Jellby]

Second one: battery life.

If you leave the unit on, even if it's in a sleepy state, it still takes some power. Not the screen though, but the processor needs power to be alive. Turning it off means it uses absolutely no power (other than maybe an internal clock?), and only the self-discharge of the battery occurs. I think someone said that turning the unit off and on again takes as much battery as ~15 minutes of idle time...

[romi]

I see. In that case it'd be good to know just how much different operations impact the battery. If ~15 mins of idle state is as much as turning it off and on, then idle state eats a lot. Oh well, people can always test for themselves I guess.

Thanks for your feedback Jellby!

[Jellby]

Originally Posted by romi

If ~15 mins of idle state is as much as turning it off and on, then idle state eats a lot.

... or turning it off and on doesn't eat so much Let's say it updates the screen 4 times. If 4 refreshes equal 15 minutes, the claimed 8000 refreshes of battery life would equal 500 hours, that's almost three weeks of idling...

[EowynCarter]

- strain on the display, even if minimal

I don't think e-ink is sensitive to that. Not sure though.

Battery life yes. And when on, sometimes buttons are accidentally pushed when the reader is in the bag.

[romi]

Jellby, love that calculation o f yours! Very smart.

EowynCarter, yeah, would be nice to know for sure. I also believe the display is not sensitive to being left "on" for long periods of time.

Saving the battery may be a good idea though as there is no way to use the reader with external power (like iPods, which can be left on hooked to the charger and used forever).

[tompe]

Originally Posted by Jellby

Second one: battery life.

Is this really an issue? If it takes nearly a week to discharge it seems to me that you will get years of use of the battery.

[Jellby]

Originally Posted by tompe

Is this really an issue? If it takes nearly a week to discharge it seems to me that you will get years of use of the battery.

I meant the time it takes the battery to discharge, not the time it takes the battery to be dead and useless and not accepting charge anymore. The latter is indeed several years, I've had my Cybook for more than two years, and the battery is still healthy.

[tompe]

Originally Posted by Jellby

I meant the time it takes the battery to discharge, not the time it takes the battery to be dead and useless and not accepting charge anymore. The latter is indeed several years, I've had my Cybook for more than two years, and the battery is still healthy.

Yes, but it will loose capacity even if you do not use it. So the important factor is if keeping it always on really will decrease the capacity significantly faster. I doubt it.

[elena]

Originally Posted by romi

Saving the battery may be a good idea though as there is no way to use the reader with external power

there's a workaround for reading while charging

[romi]

Cool, I have my mind made up: always ON. It's a fantastic option, really. I switch off the device when I'm not reading for 4+ hours, anyway. Otherwise, I'll leave it on, ready to read instantly.

Option to set the standby time is yet another feature giving this device advantage over Kindle. [Though I'm still attracted to DX's large screen for those PDFs.]

Jellby: Friend of mine who got one of the first CyBook Gen3 devices already bought a replacement battery and is furious how little it lasts.

Elena: Ah, yes, that's a great workaround. It's good to know the life-span of the device is thus not limited to replacement batteries being around.

Nice Easter!
Roman

[HarryT]

Originally Posted by tompe

Yes, but it will loose capacity even if you do not use it. So the important factor is if keeping it always on really will decrease the capacity significantly faster. I doubt it.

I think it actually will.

There are two factors which "age" a Lithium Ion battery:

1. A "natural" decay, which starts the first time it's charged. Typically a LiIon battery has a "lifetime" of perhaps 5-7 years.

2. A "charge cycle" decay. As well as its "natural" lifetime, the battery will lose a small amount of charge capacity for each charge cycle it goes through.

Item 1 will not be affected by leaving the CyBook turned on, but item 2 will, because you'll be charging it more often. After a year or two, a Cybook that's permanently turned on, and charged once a week, will almost certainly have a lower battery capacity than one that's turned off every night, and hence only goes through a charge cycle once a month.