[HowTo] Alternate way of saving battery when using 4G/LTE

c4pp4 · 5 Apr 2022, 06:52

What it does:

Script I: Switch to 2G when screen is locked and switch back to 4G when screen is unlocked. TELEports or Dekko notifications work well.
Alternative script II: Switch to 2G when screen is off and switch back to 4G when screen is on (regardless of screen lock). TELEports or Dekko notifications work well.
Alternative script III: Turn off cellular data when screen is off and turn on cellular data again when screen is on (regardless of screen lock). No TELEports or Dekko notifications when screen is off.

Precondition: Working 4G connection which drains battery when device is inactive (screen is locked or off).
Originally made for Xiaomi Mi A2 and tested on it but can be useful for any device.

Create a script "/home/phablet/lte-battery-saver"
Script I:

#!/bin/bash

primary_preference="lte"
saving_preference="gsm"
sim_slot="/ril_0"

interface=org.freedesktop.DBus.Properties
member=PropertiesChanged

dbus-monitor --session "type=signal,interface='${interface}',member='${member}'" |
while read -r line; do
        if [[ ${line} == *"com.canonical.UnityGreeter"* ]]; then
                read; read; read -r line
                if [[ ${line} == *"IsActive"* ]]; then
                        read -r line
                        [[ ${line} == *"true"* ]] && /usr/share/ofono/scripts/set-tech-preference "${sim_slot}" "${saving_preference}" 1>/dev/null
                        [[ ${line} == *"false"* ]] && /usr/share/ofono/scripts/set-tech-preference "${sim_slot}" "${primary_preference}" 1>/dev/null
                fi
        fi
done

Make script executable

chmod u+x /home/phablet/lte-battery-saver

Create an upstart session job "/home/phablet/.config/upstart/lte-battery-saver.conf"

description "LTE battery saver"

start on started dbus
stop on stopped dbus

exec /home/phablet/lte-battery-saver

Start the job

start lte-battery-saver

or reboot the phone.

NOTES (Script I and Alternative script II):

Change "/ril_0" to "/ril_1" if your data SIM is in slot 2 (see sim_slot variable)
If switching back doesn't work, try to set primary_preference variable to "any"
To switch between 3G and 2G replace "lte" with "umts" (see primary_preference variable)
To switch between 4G and 3G replace "gsm" with "umts" (see saving_preference variable)

To apply the changes, restart the job

restart lte-battery-saver

or reboot the phone.

To remove all changes

stop lte-battery-saver
rm /home/phablet/.config/upstart/lte-battery-saver.conf
rm /home/phablet/lte-battery-saver

Alternative script II:

#!/bin/bash

primary_preference="lte"
saving_preference="gsm"
sim_slot="/ril_0"

interface=com.canonical.Unity.Screen
member=DisplayPowerStateChange

dbus-monitor --system "type=signal,interface='${interface}',member='${member}'" |
while read -r line; do
	if [[ ${line} == *"int32 0" ]]; then
		read
		/usr/share/ofono/scripts/set-tech-preference "${sim_slot}" "${saving_preference}" 1>/dev/null
	elif [[ ${line} == *"int32 1" ]]; then
		read
		/usr/share/ofono/scripts/set-tech-preference "${sim_slot}" "${primary_preference}" 1>/dev/null
	fi
done

Alternative script III:

#!/bin/bash

interface=com.canonical.Unity.Screen
member=DisplayPowerStateChange

dbus-monitor --system "type=signal,interface='${interface}',member='${member}'" |
while read -r line; do
	if [[ ${line} == *"int32 0" ]]; then
		read
		dbus-send --type=method_call --dest=com.ubuntu.connectivity1 /com/ubuntu/connectivity1/Private org.freedesktop.DBus.Properties.Set string:com.ubuntu.connectivity1.Private string:MobileDataEnabled variant:boolean:false
	elif [[ ${line} == *"int32 1" ]]; then
		read
		dbus-send --type=method_call --dest=com.ubuntu.connectivity1 /com/ubuntu/connectivity1/Private org.freedesktop.DBus.Properties.Set string:com.ubuntu.connectivity1.Private string:MobileDataEnabled variant:boolean:true
	fi
done

domubpkm · 26 May 2021, 06:22

@c4pp4 Thank you!
Could be useful for the Volla UT, which I find is currently a very large power consumer despite its 4700 mA battery. Recharges every 24 hours on average (I use the internet quite regularly but..).

I installed it. Seems to work well.

But maybe it would be nice if you could make a .click of your procedure (if possible).

domubpkm · 26 May 2021, 06:42

It makes me think now that it would be useful to have a direct switch accessible by the indicator bar (network or battery) to switch directly from 4g to 2g and vice versa.

Keneda · 26 May 2021, 12:57

@domubpkm
I talked about that feature once, as i turn on 4G only when i need lot of bandwich to save battery when not needed, and got negative return...

edit : https://forums.ubports.com/topic/4406/manually-choose-lte-only-wcdma-only-lte-and-wcdma-etc/7?_=1622034590341

domubpkm · 26 May 2021, 13:31

@keneda Yes, I've read it and I still think it would be useful There is no obligation to use it.

Keneda · 26 May 2021, 18:53

@domubpkm said in [HowTo] Alternate way of saving battery when using 4G/LTE:

I still think it would be useful

I still think too ^^
BTW @c4pp4 tweak is a good thing too.

arubislander · 26 May 2021, 19:23

@keneda Lots of things could be useful, and indeed, no one would be forcing anyone to use it if they didn't want to.

But: implementing the feature would take time and effort from some developer. The feature would have to be implemented, tests would have to be written to check that the implementation is correct, and more importantly, remains correct when changes are made to the feature. And from there on out both the feature and the tests would have to be maintained in perpetuity (not having a feature encourages workarounds, removing a feature incurs rage).

So yes, from the user's perspective, more features are better, since everyone need only use what they find useful. But the developers must maintain all the features equally, irrespective of their frequency of usage. So you can understand why "I think it would be useful" is not a sufficiently compelling argument to take on the burden of maintenance of a new feature.

domubpkm · 28 May 2021, 09:11

One way to save battery power, as seen with my Volla, is to turn off cellular data when not needed and turn it back on when needed. This does not prevent the use of phone and SMS functions.
It is the fact of being connected to a 4G, 3G or even 2G network that really drains the battery and even more so when the sky is not clear (inappropriate atmospheric conditions): there the overconsumption can get out of hand.

Keneda · 28 May 2021, 10:51

@domubpkm Problem is that prevents from receiving MMS.

domubpkm · 28 May 2021, 11:41

@keneda Yes, nothing is perfect! For mails, they arrive well once the cellular data has been reactivated. For MMS, when cellular data OFF, a SMS informs the recipient that the MMS could not be recovered.

jezek · 28 May 2021, 14:38

@domubpkm There is a pull request waiting for approval, which handles all the trouble when receiving MMS while cellular data is off. Feel free to test and report.

Mario.CH · 28 May 2021, 16:57

Hello c4pp4,
thanks for your work on the topic of battery saving.
I did the test on my Sony Xperia X (F5121). The device switches to G2 as promised. However, when the device wakes up, it does not switch back to LTE.
Unfortunately for me, my network provider no longer supports G2, so I have no connection to the antenna, i.e. "The subscriber is currently unavailable".:beaming_face_with_smiling_eyes:
Now I want to remove the script or the changes I made.
Is that possible?
And how do I do that?
Could you support me.
Greetings Mario

Translated with www.DeepL.com/Translator (free version)

domubpkm · 28 May 2021, 17:10

To do that, i deleted the script (lte-battery-saver) and the upstart session job (lte-battery-saver.conf) and rebooted the smartphone.

c4pp4 · 28 May 2021, 18:57

@mario-ch Hello,
what kind of connections are available in your case? I can help you to tweak the script for your needs.

Anyway to take back the changes, remove both files:

rm /home/phablet/lte-battery-saver
rm /home/phablet/.config/upstart/lte-battery-saver.conf

Mario.CH · 28 May 2021, 19:09

@c4pp4 As it seems, or rather I think 3G would work.

c4pp4 · 28 May 2021, 19:31

@mario-ch You mean switch to 3G when display is off and switch back to 4G when on?

Mario.CH · 28 May 2021, 19:35

@c4pp4 yep, that's exactly what i mean.

c4pp4 · 28 May 2021, 19:59

@mario-ch Ok give me some time, I will test it on my xperia x and let you know.

BTW you can try it on your own when you replace "gsm" with "umts".

c4pp4 · 4 Jun 2021, 20:55

@mario-ch In case of Xperia X (maybe it's related to Halium 7.1) we have to set it to "lte" option instead of "any", so the script for your needs (3G<->4G) is here:

#!/bin/bash

interface=org.freedesktop.DBus.Properties
member=PropertiesChanged

dbus-monitor --session "type=signal,interface='${interface}',member='${member}'" |
while read -r line; do
        if [[ ${line} == *"com.canonical.UnityGreeter"* ]]; then
                read && read && read -r line
                if [[ ${line} == *"IsActive"* ]]; then
                        read -r line
                        [[ ${line} == *"true"* ]] && /usr/share/ofono/scripts/set-tech-preference /ril_0 umts 1>/dev/null
                        [[ ${line} == *"false"* ]] && /usr/share/ofono/scripts/set-tech-preference /ril_0 lte 1>/dev/null
                fi
        fi
done

domubpkm · 29 May 2021, 18:29

@jezek said in [HowTo] Alternate way of saving battery when using 4G/LTE:

which handles all the trouble when receiving MMS while cellular data is off

Hello. You done a huge work..! congratulations.

Does it mean that the main purpose of the work is that MMS could be received normally with cellular data OFF ?