A (stupid?) question about stand-by mode

[italianReader]

I'm not really sure about the usefulness of the stand-by mode in the devices with an i-ink screen.

I think it should increase the battery-life but...why?

What's the difference between using it and leaving the e-book reader turned on on a "normal" page?

thanks for your replies

[Sweetpea]

Originally Posted by italianReader

I'm not really sure about the usefulness of the stand-by mode in the devices with an i-ink screen.

I think it should increase the battery-life but...why?

What's the difference between using it and leaving the e-book reader turned on on a "normal" page?

thanks for your replies

Stand-by locks the keys. If I take my Mini as example: it has two paging buttons on the right side, a thumbwheel on the left, 10 number buttons on the bottom and a large "Menu/OK" button.

If I don't lock my device, before putting it in my bag, I won't be sure that I'll be able to continue my story from where I left it. I might have left the book or I might have moved to a completely different part of that book.

Often, it's not called a "stand-by", but rather a keyboard-lock...

[italianReader]

It think you are right but...what about the battery life?

I think that maybe it disables the touchscreen (if present) and this should save a bit of energy...is it possible?

[Sweetpea]

I don't have a touchscreen, so I can't speak about that.

For the battery, it doesn't matter if you put the device on stand-by or not. Not even turning it off the whole time would matter. E-ink only draws energy when the screen gets refreshed. And that's when you go to a next page. So, if you leave the device "on", or on stand-by or "off", if you don't refresh the page, you don't draw energy.

(naturally, a battery will drain by itself, nothing can be done about that, at least, not with the current battery technology ...)

[mrscoach]

I'm going to sound like Forrest Gump here, but my mom had two sayings about 'stupid' questions.

1. There are no stupid questions, only stupid answers.

2. The only stupid question is the unasked one.

Okay, hijacking over, we now return you to your regularly scheduled thread. LOL

[Sweetpea]

Originally Posted by mrscoach

I'm going to sound like Forrest Gump here, but my mom had two sayings about 'stupid' questions.

1. There are no stupid questions, only stupid answers.

2. The only stupid question is the unasked one.

Okay, hijacking over, we now return you to your regularly scheduled thread. LOL

A math teacher once told me the same (but in Dutch, naturally!)

[HarryT]

Originally Posted by Sweetpea

For the battery, it doesn't matter if you put the device on stand-by or not. Not even turning it off the whole time would matter. E-ink only draws energy when the screen gets refreshed. And that's when you go to a next page. So, if you leave the device "on", or on stand-by or "off", if you don't refresh the page, you don't draw energy.

That's incorrect.

The screen doesn't use any power when it's not doing a page turn, but an eBook reader is a computer. It has a CPU and memory, all of which use power, just like they do on any other computer.

Generally, "stand-by mode" puts a device into a very low power mode, where the CPU is "hibernating" and using a lot less power than it does in normal operation.

[Sweetpea]

Originally Posted by HarryT

That's incorrect.

The screen doesn't use any power when it's not doing a page turn, but an eBook reader is a computer. It has a CPU and memory, all of which use power, just like they do on any other computer.

Generally, "stand-by mode" puts a device into a very low power mode, where the CPU is "hibernating" and using a lot less power than it does in normal operation.

I know it's technically incorrect, but if I can leave my device "on" for 4 months without having to charge the battery (didn't use it a lot during the winter months), that drain is negligable...

[Shaggy]

Originally Posted by HarryT

That's incorrect.

The screen doesn't use any power when it's not doing a page turn, but an eBook reader is a computer. It has a CPU and memory, all of which use power, just like they do on any other computer.

Generally, "stand-by mode" puts a device into a very low power mode, where the CPU is "hibernating" and using a lot less power than it does in normal operation.

Exactly. There's a common misconception out there that eInk devices don't use power except to change the page. The truth is, eInk screens don't use power exept to change the page, but the rest of the device, as Harry says, is basically a computer. There are lots of things inside the case that use power which have nothing to do with the eInk screen.

[HarryT]

Originally Posted by Sweetpea

I know it's technically incorrect, but if I can leave my device "on" for 4 months without having to charge the battery (didn't use it a lot during the winter months), that drain is negligable...

That's the BeBook Mini, is it? It appears as if it actually does pretty much totally shut down in sleep mode, but it's the exception, rather than the rule. Most devices do keep running in a more or less active state, even when "asleep". Eg, the Cybook Opus will drain its battery in about a week; the nook in only a few days.

[Shaggy]

Originally Posted by Sweetpea

I know it's technically incorrect, but if I can leave my device "on" for 4 months without having to charge the battery (didn't use it a lot during the winter months), that drain is negligable...

Your device probably automatically went into it's low power mode during that time. The reason the drain was negligible is because it was in "stand-by". Otherwise, the drain is probably much higher.

[Maggie Leung]

Does anyone know how long a fully charged Kindle can go between charges if you don't use it? I'm hanging on to my Kindle, but I'm doing all my reading on iPad, it turns out. I wanna know how frequently I have to charge my Kindle to keep the battery from croaking.

[Shaggy]

Originally Posted by Maggie Leung

Does anyone know how long a fully charged Kindle can go between charges if you don't use it? I'm hanging on to my Kindle, but I'm doing all my reading on iPad, it turns out. I wanna know how frequently I have to charge my Kindle to keep the battery from croaking.

Amazon says 2 weeks with wireless turned off. I don't know how much of that is active use vs standby. It might be longer if you're not using it at all.

However, there is a difference between how long to wait before you need to charge the battery to keep it from going dead, vs how long to wait before you need to charge the battery in order to preserve it's long term life expectancy.

I don't know what type of battery the Kindle has off the top of my head, but most of these devices typically have a lithium-ion battery (or a variant of one). These types of batteries do better if you don't wait until they're fully drained before charging them. A big charge cycle like that can actually reduce their life expectancy. It's better to top them off more frequently, requiring a smaller charge cycle, and only let them fully drain once in awhile in order to keep the meter calibration from drifting. Personally, I would only let it get down to about 50% - 60% before charging, then after doing that 30 or so times, let it drain completely once, then start topping off for 30 times again... etc.