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[Bug] Battery saving mode does not activate on the set percentage [answered]

Tracked by Jolla (In release)

asked 2019-03-22 12:40:33 +0300

Mariusmssj gravatar image

updated 2019-03-22 13:37:25 +0300

It appears with that with new 3.0.2 update the battery saving mode does not become active when the battery drops below 20% which I have set the battery saving mode threshold. It can be activated manually but not automatically.

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The question has been closed for the following reason "the question is answered, an answer was accepted" by jiit
close date 2019-03-25 13:40:56.818800


It doesn't really help when you change the question to something completely different as all the previous answers now seem to have to connection to the question whatsoever.

The original question was:

It appears with that with new 3.0.2 update the battery saving mode does not have any indicator to show that it is currently active. I feel that there should be the icon next to the battery or battery icon change to indicate that battery saving mode is currently active.

ossi1967 ( 2019-03-23 19:21:08 +0300 )edit

Anyway, what does this battery saving mode do? I would like to know as many mechanisms that were "sold" as battery saving do not work on modern mobile hardware or are actually counterproductive. On modern mobile CPUs emptying RAM, reducing RAM usage cache or reducing clock rates actually increase battery drain instead of reducing it.

Shoppinguin ( 2019-03-24 20:13:56 +0300 )edit

@Shoppinguin: Check the answer of spiiroin, please.

jovirkku ( 2019-03-25 12:30:08 +0300 )edit

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answered 2019-03-23 17:33:03 +0300

spiiroin gravatar image

updated 2019-03-28 13:16:29 +0300

Power saving mode is an old feature inherited all the way from Nokia Maemo devices like N900 i.e. Sailfish OS has kind of supported it under the hood from day zero.

What changed now is that I became officially supported feature: It has a place in the settings UI, it has received testing attention, some quirks/hiccups with triggering etc have been fixed, and it hopefully will become more useful in the future.

Currently the only real effects of PSM getting triggered are:

  • Display brightness is toned down
  • Background synchronization tasks are skipped
  • The indicator icon is shown in status bar

The relevant settings can be manipulated from CLI with mcetool options:

-p, --set-power-saving-mode=<enabled|disabled>
-T, --set-psm-threshold=<10|20|30|40|50>
-F, --set-forced-psm=<enabled|disabled>

(Note that - despite the instructions above - the threshold can be freely set to 0...100 % range)

EDIT: 2019-03-25

Looks like there is indeed a glitch in how initial default state is configured vs. interpreted by the settings UI.

Initial configuration state is "Threshold = 20%, feature = disabled". The feature is enabled only when the threshold value changes -> as long as user does not change the value / selects 20%, the feature stays disabled.

Remedy: Selecting any other threshold (say 10%) changes the situation to "Threshold = 10%, feature = enabled". After that the feature stays enabled (and also 20% can be selected).

EDIT: 2019-03-28

Fix for the setting glitch exists and should be included in sfos >= 3.0.3.x

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That's wonderful thank you :)

Mariusmssj ( 2019-03-25 13:48:34 +0300 )edit

Which exactly background synchronization tasks are skipped? I've tested it overnight and got 4% drop over 10h which is amazing, considering putting this on at 100%. Did get email notifications, so wondering what exactly gets stopped

szopin ( 2019-03-26 15:05:25 +0300 )edit

@szopin: All tasks handled via msyncd a.k.a. buteo sync framework - which should include email / contacts / calendar / etc.

What changed: Basically msyncd already had logic for skipping actions when "battery=low" and some placeholder bits of code for doing the same on "psm=active" -> the missing pieces were added.

Note that this skipping applies only for actions taken due to synchronization scheduling rules. If applications might request explicit synchronization, those should still get executed. Still, if you get email notifications when psm is definately active without having the email application open -> that probably should not happen -> getting logs might be useful.

While all of this has some effect on idle behavior, I'd perhaps attribute major improvements to other changes made elsewhere (e.g. wlan driver perhaps).

spiiroin ( 2019-03-27 09:25:54 +0300 )edit

@spiiroin Thanks, it's a jolla C in my case, so doubt it on the driver part, maybe the syncing was too aggressive in my settings (especially since I don't have contacts/calendar syncing enabled for any of the accounts, only email/twitter/IM or maybe having gtalk sync endlessly alone is such a hog?), but the savings are really huge, and emails come through (even with email app closed), which makes me want to put this on at 100% most of the time. Which logs exactly would be useful?

Edit: looks like having email account set up as 'always up to date' makes the emails come through even in PSM, after changing to 'every X min/h' made no email notifications come through

szopin ( 2019-03-27 12:36:44 +0300 )edit

answered 2019-03-22 13:01:36 +0300

ziellos gravatar image

The leaf icon is meant as indicator of battery saving mode.

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seems to be a bug with mine as when the battery drops below 20% which I have set the battery saving mode does not get activated.

Mariusmssj ( 2019-03-22 13:35:27 +0300 )edit

@Mariusmssj Check the first answer above, which is given by Jolla itself. It is a bug! He's telling some remedy for it.

Vieno ( 2019-03-28 20:29:09 +0300 )edit

answered 2019-03-22 12:56:53 +0300

rgrnetalk gravatar image

updated 2019-03-22 14:45:58 +0300

olf gravatar image

screenThere should be a leaf next to the battery percentage see screenprint

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Nice, you changed the thresholds manually. Can you tell the file you edited?

Spark ( 2019-03-22 13:49:43 +0300 )edit

It's also possible to activate battery saving mode manually by the toggle.

What I would really like to know: what does it actually do (apart from dimming display backlight)? In idle mode (without display active) there are no mensurable savings, as far as I can tell.

ziellos ( 2019-03-22 14:03:28 +0300 )edit

@Spark: Let's not edit any files but use the UI options in Settings > Battery. Or else there would be confusion on what is broken or a bug, and what not. Thanks.

jovirkku ( 2019-03-25 12:27:58 +0300 )edit

@ziellos: Check the answer of spiiroin, please.

jovirkku ( 2019-03-25 12:28:57 +0300 )edit

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Asked: 2019-03-22 12:40:33 +0300

Seen: 601 times

Last updated: Mar 28 '19