PW4 Minimizing battery consumption

[NiLuJe]

FWIW, I just remembered why I mentioned that it was suspend-to-disk-ish: it's not the stock Linux code, but this thing. I think .

(The "Deep Sleep" thingy, I mean. Everything else is the usual suspend to ram).

[Junket]

Interestingly, different terminology is sometimes employed in N. America vs. UK vs. Europe and elsewhere. Just to confuse us all.

suspend to ram is usually called sleep in N. America
suspend to disk (aka deep sleep) is usually called hibernation in N. America

I have no idea which terms are most common in Europe.

[j.p.s]

Originally Posted by Junket

Referenced thread

The result, e.g. about 5% drain /month (PW4, deep sleep) implies zero processor activity as the discharge rate is what you would expect for a battery alone sitting on a shelf (2% per month self-discharge, plus 2 - 3% per month for the battery protection circuit).

Originally Posted by Junket

Deep sleep + airplane mode was about 5% drain /month
Manual shutdown command brings that down to 3% drain /month

Can you point me to where PW4 in deep sleep + airplane mode was reported?

I've looked and just can not find it in the referenced thread except for the post where I requested it.

[NiLuJe]

@Junket: Wild guess: because sleep/hibernation is the Windows nomenclature? .

[handyguy]

I was getting about 3 days with python sleep() and about 8 days with rtcwake -m mem.

[Junket]

@NiLuJe
Without a doubt. Big advertising budgets dominate, unless you are IBM



@j.p.s
I took the second and third lines of ilovejedd's results to be deep sleep because Amazon says that the PW4 will automatically transition to deep sleep (aka power saver mode) after approx 45 min of inactivity.

[j.p.s]

Originally Posted by Junket

@j.p.s
I took the second and third lines of ilovejedd's results to be deep sleep because Amazon says that the PW4 will automatically transition to deep sleep (aka power saver mode) after approx 45 min of inactivity.

I don't have a PW4, but I'm under the impression that it has an option to disable deep sleep.

I guess ilovejedd will have to clarify the setting used.

[Junket]

I have seen several people write that there is a PW4 menu item to disable this and the more specific claim that it was an option in fw v. 5.10.2.

Settings > All Settings > Device options > Advanced Options > Power Saver

But this setting does not appear in my PW4 menu for either 5.10.1.3 or 5.10.2. Possibly because my Kindle is unregistered.

[ilovejedd]

Originally Posted by Junket

I have seen several people write that there is a PW4 menu item to disable this and the more specific claim that it was an option in fw v. 5.10.2.

Settings > All Settings > Device options > Advanced Options > Power Saver

But this setting does not appear in my PW4 menu for either 5.10.1.3 or 5.10.2. Possibly because my Kindle is unregistered.

Yep, the Advanced Options are only available on registered Kindles.

I have no idea whether Power Saver/deep sleep works by default on unregistered Kindles (pretty much all Kindles tested except for one). I'm inclined to think yes considering these results:

• PW4 5.10.1.3: unregistered, airplane mode on: 100% - 95% = 5% (Power Saver/deep sleep mode: unknown)
• PW4 5.10.1.3: unregistered, airplane mode off: 98% - 92% = 6% (Power Saver/deep sleep mode: unknown)
• PW4 5.10.1.3: registered, airplane mode off, deep sleep: 99% - 91% = 8%

I'm primarily using the Kobo Libra H2O now and I can't find my lone registered PW4 for retest.

[mergen3107]

@ilovejedd
Sorry if I am missing out, but what are these battery percents? Like 100% - 95% = 5% : is it the battery drain during a specific period?

[Junket]

Thanks for the clarification @ilovejedd

Unless contrary information arises, I'm inclined to believe that power saver is enabled by default. That would be consistent with the results you observed. There are a handful of tech journalist "articles", all saying the same. And when I asked an Amazon CSR, he "checked" and said that it was on, unless the user changed the option.

It's more ambiguous for an unregistered Kindle but it seems reasonable that it would default the same as well.

[ilovejedd]

Originally Posted by mergen3107

@ilovejedd
Sorry if I am missing out, but what are these battery percents? Like 100% - 95% = 5% : is it the battery drain during a specific period?

https://www.mobileread.com/forums/sh...d.php?t=322331

initial charge level - charge level after 27 days = percent drain

[j.p.s]

Originally Posted by Junket

Thanks for the clarification @ilovejedd

Unless contrary information arises, I'm inclined to believe that power saver is enabled by default. That would be consistent with the results you observed. There are a handful of tech journalist "articles", all saying the same. And when I asked an Amazon CSR, he "checked" and said that it was on, unless the user changed the option.

It's more ambiguous for an unregistered Kindle but it seems reasonable that it would default the same as well.

I agree with all that, but I have vague memories of ilovejedd posting in some other thread that she did not like the power save mode and had disabled it. Of course there is no telling which of her vast fleet of PW4s that applied to. I am not disputing how close to power off deep sleep is, just looking for unambiguous test results.

I'm actually most interested in how close to power off battery usage the Oasis 2 is in deep sleep. Maybe Sirtel would be willing to do the test since she doesn't use hers much.

[ilovejedd]

Originally Posted by j.p.s

I agree with all that, but I have vague memories of ilovejedd posting in some other thread that she did not like the power save mode and had disabled it. Of course there is no telling which of her vast fleet of PW4s that applied to. I am not disputing how close to power off deep sleep is, just looking for unambiguous test results.

It was airplane mode I don't bother with as I do use WhisperSync on my registered Kindles. On the unregistered ones, I leave wi-fi on as I frequently download content via experimental browser+Calibre PHP server or via KOReader+Dropbox.

The lone registered PW4 I do have was tested in Power Save mode on + Wi-Fi on.

All the rest are unregistered so I'm actually unable to change the Power Save mode from whatever the default is (which based on test results is presumably on).

[j.p.s]

Originally Posted by ilovejedd

All the rest are unregistered so I'm actually unable to change the Power Save mode from whatever the default is (which based on test results is presumably on).

I don't have a PW4. My registered KOA2 with very early firmware does not have an option to toggle power saving. If it has been off long enough to enter power saving, it displays the message: 'WAKING UP..." for a few seconds while it wakes up.

If the PW4 has a waking up message, it should be easy to find out what the default state for an unregistered PW4 is.