Charging Limitation for enhanced Battery Life (Feature Request)

answered 2015-03-05 15:11:48 +0200

LVPVS
3306 ●58 ●87 ●78

updated 2018-02-04 09:07:06 +0200

Hei,

Update for SailfishX

I was afraid this hack won't work on SailfishX. But, hey! SailfishX has a better way to do it:

/sys/class/power_supply/battery/baterry_charge_enable

If '0' is written in it, battery charging stops immediately. And the discharging is way less than JP1301 had. I believe, in that case, the external power supply was logically cut and the phone went on battery only. But this in case, USB power supply is used and the battery is only there for buffering.

I just wanted to share my experiences.

/Update for SailfishX

I refined my method over time. I am leaving the original script as well, but I am posting the way I currently use it.

Here it goes:

I created two short scripts, one for starting, one for stopping charging. All the timeing and battery checking is done by Situations App via the script 'What'. I figured that this leaves the least amount of over-head.

Situations created:

'Start charging':
'When': Accessory = Charger && Battery !> 70% remaining
'What': Command: /the/path/to/charging_start.sh

'Stop charging':
'When': Accessory = Charger && Battery !< 80% remaining
'What': Command = /the/path/to/charging_stop.sh

'Charging':
'When': Accessory = Charger
'What': Command (at end) = /the/path/to/charging_start.sh

Contents of 'charging_start.sh':

#!/bin/sh
# We need to take control over this, every time after reboot.
chmod 777 /sys/class/power_supply/usb/charger_disable
# Set it to allow charging.
echo 0 > /sys/class/power_supply/usb/charger_disable

Contents of 'charging_stop.sh':

#!/bin/sh
# We need to take control over this, every time after reboot.
chmod 777 /sys/class/power_supply/usb/charger_disable
# Set it to stop charging.
echo 1 > /sys/class/power_supply/usb/charger_disable

Start of the original post:

I managed to patch together a shell script that handles the charging on the Jolla phone. It limits charging at around 80% of SoC and (if charger was not disconnected) starts charging at around 40% of SoC. To make full use of it, I installed Situations app from Jolla Store and created a situation that is triggered when charger accessory is connected and runs my script.

The contents of charging_control.sh script:

#!/bin/sh
# We need to take control over this, every time after reboot.
chmod 777 /sys/class/power_supply/usb/charger_disable
# Set it to allow charging.
echo 0 > /sys/class/power_supply/usb/charger_disable

#Set the variables.
soc=$(cat /sys/class/power_supply/battery/energy_now)
present=$(cat /sys/class/power_supply/usb/present)
state=$(cat /sys/class/power_supply/usb/charger_disable)

#Start the loop and keep cycling while the charger is present.
while (($present > 0))
do
present=$(cat /sys/class/power_supply/usb/present)
soc=$(cat /sys/class/power_supply/battery/energy_now)

#If SoC is over around 80%, charging is disabled.
if (($soc > 5400000 && $state == 0)); then
echo 1 > /sys/class/power_supply/usb/charger_disable
state=1
fi

#If the SoC drops below around 40% and the charger is still connected, charging is enabled.
if (($soc < 2500000 && $state == 1)); then
echo 0 > /sys/class/power_supply/usb/charger_disable
state=0
fi

#Sleep for a while before re-checking the situations.
sleep 120
done

#Re-enable charging when the charger is removed. Preparing for the next time.
if (($present < 1)); then
echo 0 > /sys/class/power_supply/usb/charger_disable
fi

The contents of the charging_control.desktop file:

[Desktop Entry]
Type=Application
Name=Charging Control
#The location of my script:
Exec=/home/nemo/.scripts/charging_control.sh
Icon=icon-l-terminal

The .desktop file can be put into any of the two folders:

1. /home/nemo/.local/share/applications

2. /usr/share/applications

Limitations:

With Situations app (by Pastilli Labs) currently only the second location works.

The script can only be run as root.

Disclaimer: As always, proceed at your own risk. I will be sorry if you happen to brick you device, but it won't be my fault. This script is working for me, though.

I know that this script is not at all professional. It might have limitations or defects. If you notice one, please let me know, so I can update my post.

PS.: If somebody feels to create a daemon out of the above, please do it. But send me a copy.

LVPVS out.

answered 2015-09-22 14:29:15 +0200

Niju
166 ●4 ●8 ●11

This is unnecessary. 100% charge on a lithium battery isn't actually 100% of the total possibility of the battery as this would put the lithium battery in an unstable potentially explosive state.

Consumer batteries tend to operate in the 10-90% capacity range, so when you charge your phone/laptop etc battery, it may read 100% but in actuality it is only around 90% of the total capacity possible of the battery, same with 0% actually being around 10% of the battery. If you were to fully discharge the lithium battery, it would most likely not work again as lithium batteries like to operate in particular regions and also why memory effects don't exist.

So in summary, by messing around with the levels you are actually doing yourself a disservice, just leave it as it is, where it works most optimally.

Source: I'm an EE.

answered 2014-09-10 21:23:25 +0200

dsilveira
7805 ●77 ●110 ●101

That would be a cool feature, but don't forget that fully discharging also reduces battery life, so a complete solution would provide dis/charge intervals, with good suggested defaults for different scenarios' needs.

answered 2014-10-14 18:45:55 +0200

Philippe De Swert
7698 ●74 ●88 ●91

There is the /sys/class/power_supply/usb/charger_disable entry in sysfs. You will have to chmod it on every boot and you can disable charging by writing 1, enable again by writing a 0. This was purely done for testing and is not really recommended to use. But in case you really want you can write something that keeps track of the charging state (you can also read that from sysfs) and set/unset the charging based on that.

Anyway at your own risk and not recommended.

answered 2016-07-11 14:51:56 +0200

xkr47
796 ●5 ●10 ●16

http://xkr47.outerspace.d...

Try my app Charger Control available through Warehouse to control when to charge and not. Next version hopefully adds support for automatic switching at configured charge levels. Works only on the original Jolla phone for now.

answered 2016-02-15 14:18:02 +0200

neter
61 ●5 ●5

Little usage experience from me. When I started to use these scripts 3-4 months ago the capacity of the battery was ~90%. With the scripts I'm charging the battery to 61% and discharge it to 59%, all night on charger, during the day the charge level drops to 40-50% (depends on the usage), and in the evening on charger again. During these 3-4 months there was constant increasing of the battery capacity. Now it shows 102.10% capacity (8.15 Wh vs. 7.98 Wh by design) and it looks like it will continue to increase in the (near) future. I'm curious if I unlocked some hidden capacity with that usage model, or (probably) there is a bug in the controller/sensors/system. And what will happen if I make a full charge now - if I will see wrong percent of the charge level, or an explosion :)