Thanks, nice find!
I’ll try to add this to Battery Buddy at some point 
It’s a bit unfortunate that we have two apps doing essentially the same thing.
Battery Buddy didn’t exist back in 2018 when I first started working on that topic, so I’ve built my own app for this.
But it’s still great to see that having this stuff documented helps people
Unfortunately the XA2 has no lrc_enable / lrc_socmax options. Haven’t found an alternative. Which is weird, as it all qualcomm and the even the JP1-SOC had this option.
I guess you’ve already checked all subdirectories in /sys/class/power_supply/?
Maybe it’s part of the BMS (Battery Management System) or some other component on the XA2…
Yes. There are many things, but no lrc-stuff. There might be alternatives, but I don’t think it’s wise to start writing some numbers to all those options, hoping it helps.
Hmm, interesting.
Could you post a full ( ls -lah ) directory listing for battery/ (and battery_ext, if present)?
The Xperia X and 10 II both allow to set the charging current, at least to some extent.
So you could disable charging that way, if possible.
Or at least slow down charging a lot. But I’m unsure about the effects of a low but still nonzero charging current in the long term. This approach might also be more inefficient in case the internal circuitry just burns the unwanted energy…
[root@XperiaXA2 battery]# ls -lah
total 0
drwxr-xr-x 3 root root 0 Jul 17 21:11 .
drwxr-xr-x 7 root root 0 Jul 17 21:11 ..
-rw-r--r-- 1 root root 4.0K Aug 8 14:34 capacity
-r--r--r-- 1 root root 4.0K Aug 10 13:30 charge_counter
-r--r--r-- 1 root root 4.0K Aug 10 23:38 charge_done
-r--r--r-- 1 root root 4.0K Aug 10 23:38 charge_type
-r--r--r-- 1 root root 4.0K Aug 10 23:38 charger_temp
-r--r--r-- 1 root root 4.0K Aug 10 23:38 charger_temp_max
-r--r--r-- 1 root root 4.0K Aug 10 23:38 constant_charge_current_max
-r--r--r-- 1 root root 4.0K Aug 10 13:30 current_now
-r--r--r-- 1 root root 4.0K Aug 10 23:38 current_qnovo
lrwxrwxrwx 1 root root 0 Aug 10 23:38 device -> ../../../800f000.qcom,spmi:qcom,pm660@0:qcom,qpnp-smb2
-r--r--r-- 1 root root 4.0K Aug 10 23:38 die_health
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 dp_dm
-r--r--r-- 1 root root 4.0K Aug 8 14:34 health
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 input_current_limited
-rw-rw-rw- 1 root root 4.0K Aug 10 16:00 input_suspend
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 parallel_disable
drwxr-xr-x 2 root root 0 Aug 10 23:38 power
-r--r--r-- 1 root root 4.0K Aug 10 13:30 present
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 rerun_aicl
-r--r--r-- 1 root root 4.0K Aug 10 23:38 set_ship_mode
-r--r--r-- 1 root root 4.0K Aug 8 14:34 status
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 step_charging_enabled
lrwxrwxrwx 1 root root 0 Aug 8 14:34 subsystem -> ../../../../../../../../class/power_supply
-rw-r--r-- 1 root root 4.0K Aug 10 23:38 sw_jeita_enabled
-rw-r--r-- 1 root root 4.0K Jul 17 21:11 system_temp_level
-r--r--r-- 1 root root 4.0K Aug 10 13:30 technology
-r--r--r-- 1 root root 4.0K Aug 8 14:34 temp
-r--r--r-- 1 root root 4.0K Aug 10 23:38 type
-rw-r--r-- 1 root root 4.0K Aug 8 14:34 uevent
-r--r--r-- 1 root root 4.0K Aug 10 23:38 voltage_max
-r--r--r-- 1 root root 4.0K Aug 10 13:30 voltage_now
-r--r--r-- 1 root root 4.0K Aug 10 23:38 voltage_qnovo
[root@XperiaXA2 battery]# cd ../bms
[root@XperiaXA2 bms]# ls -lah
total 0
drwxr-xr-x 3 root root 0 Aug 10 23:39 .
drwxr-xr-x 3 root root 0 Aug 10 23:39 ..
-r--r--r-- 1 root root 4.0K Aug 10 23:39 battery_type
-r--r--r-- 1 root root 4.0K Aug 10 23:39 capacity
-r--r--r-- 1 root root 4.0K Aug 10 23:39 capacity_raw
-rw-r--r-- 1 root root 4.0K Aug 10 23:39 cc_step
-rw-r--r-- 1 root root 4.0K Aug 10 23:39 cc_step_sel
-r--r--r-- 1 root root 4.0K Aug 10 23:39 charge_counter
-r--r--r-- 1 root root 4.0K Aug 10 23:39 charge_full
-r--r--r-- 1 root root 4.0K Aug 10 23:39 charge_full_design
-r--r--r-- 1 root root 4.0K Aug 10 23:39 charge_now
-r--r--r-- 1 root root 4.0K Aug 10 23:39 charge_now_raw
-rw-r--r-- 1 root root 4.0K Aug 10 23:39 constant_charge_voltage
-r--r--r-- 1 root root 4.0K Aug 10 23:39 current_now
-r--r--r-- 1 root root 4.0K Aug 10 23:39 cycle_count
-rw-r--r-- 1 root root 4.0K Aug 10 23:39 cycle_count_id
-r--r--r-- 1 root root 4.0K Aug 10 23:39 debug_battery
lrwxrwxrwx 1 root root 0 Aug 10 23:39 device -> ../../../800f000.qcom,spmi:qcom,pm660@0:qpnp,fg
drwxr-xr-x 2 root root 0 Aug 10 23:39 power
-r--r--r-- 1 root root 4.0K Aug 10 23:39 resistance
-r--r--r-- 1 root root 4.0K Aug 10 23:39 resistance_id
-r--r--r-- 1 root root 4.0K Aug 10 23:39 soc_reporting_ready
lrwxrwxrwx 1 root root 0 Aug 10 23:39 subsystem -> ../../../../../../../../class/power_supply
-r--r--r-- 1 root root 4.0K Aug 10 23:39 temp
-r--r--r-- 1 root root 4.0K Aug 10 23:39 time_to_empty_avg
-r--r--r-- 1 root root 4.0K Aug 10 23:39 time_to_full_avg
-r--r--r-- 1 root root 4.0K Aug 10 23:39 type
-rw-r--r-- 1 root root 4.0K Aug 10 23:39 uevent
-r--r--r-- 1 root root 4.0K Aug 10 23:39 voltage_max_design
-r--r--r-- 1 root root 4.0K Aug 10 23:39 voltage_now
-r--r--r-- 1 root root 4.0K Aug 10 23:39 voltage_ocv
There is no battery_ext directory. I guess the writable files are most interesting?
In general, yes. There are writeable files which are not effectively writeable, though.
Thanks for the list. Seems like LRC-like functionality is indeed missing. On the other hand, it probably isn’t that hard to patch the kernel to stop charging at some level, because all the needed infra (determining state of charge and disabling charging completely) is already there…
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Is there an installable package for the app?
You can manually download the RPM from Gitlab or install via Chum to automatically get updates.
For Chum, see GitHub - sailfishos-chum/main: Documentation and issues and Announcing sailfishos:chum .
From the data above, the app currently doesn’t work on the XA2 (yet). Please let me know if it doesn’t work for you!
In general, the functionality is similar to Battery Buddy, only my approach is different (more in the direction of less complexity/overhead and therefore less features).
Thanks. I was looking for that link. Works on 10 II, at least the battery meter stops advacing after the preset max charge is set. Hopefully it really does stop after that, i.e. it doesn’t just fix the “interface” part.
Come to think of it, that’s a great idea for an easter egg/april fools’ joke! I’m unsure on how to achieve that, but I’m sure that would make values beyond 100% possible 
Back to topic:
Recently I’ve observed that charging may not be resumed under very special conditions:
- Plug phone into a computer’s USB port and keep it plugged in all the time
- Put computer to sleep/suspend (no current is provided by the computer)
- Wait till phone looses a few percent points of charge so that it drops below the configured level
- Wake up the computer (USB power available again)
- Phone should start charging again, but actually doesn’t
Physically re-plugging the phone triggers charging again (if it’s below the charging level).
As I’m unsure whether that’s a fault on the side of the computer or phone, USB power negotiation, … I’m interested in user reports on this.
Hi! have also a look at old thread "charge management for battery health " on old sfos forum
@takimata I think it’s motherboard and OS-specific. For me it resumes charging after exiting standby.
It also doesn’t show the charging had stopped when the host is in sleep mode, even though the charging isn’t really occurring. Could be Sailfish interpreting any active USB connection as charging.
Which device are you using?
Hmm, I can’t reproduce that. Maybe you are using an USB port on a laptop which does some USB charging even when powered off (can be usually configured in the BIOS)?
Nevertheless, in general, you are right - any positive charging current is interpreted as charging - even when it’s just something like 50 mA, for which charging takes forever…
Xperia 10 II.
Testing on a regular desktop PC, not a notebook.
I did not tried this yet, however today I noticed that the threshold that are respected using a the battery charger are NOT respected when the smartphone is connected to the a USB laptop charging port on USB tethering mode:
mcetool | grep -i charg
Display on at charging start 3000 ms
Charger cable: connected
Charger state: on
Charging mode: apply-thresholds
Charging override: disabled
Charging enable limit: 95 (%)
Charging disable limit: 90 (%)
I am going to try the solution and I will report if also address this shortcoming. In particular these which need to set every boot:
echo 1 >/sys/class/power_supply/battery_ext/lrc_enable;
echo 95 >/sys/class/power_supply/battery_ext/lrc_socmax;
echo 90 >/sys/class/power_supply/battery_ext/lrc_socmin;
echo 1 >/sys/class/power_supply/battery/lrc_enable
Unless a specific application is installed because this report nothing:
sysctl -a 2>/dev/null | grep -iE "lrc|batt|charg"
Update
After those commands above, the battery charge works as expected when the smartphone is connected to a laptop USB for tethering. The only part that is still missing is to write those values at boot time, but a simple solution is to install cron and make it run /etc/rc.local at each @reboot. A suggestion for a more stylish solution will be appreciated.
Can someone tell me the role of this kernel feature?
/sys/class/power_supply/battery_ext/lrc_not_startup
Zero by default.
Q: Is there a way to change the charging percentage display in the top line of the phone (next to time and 4G signal strength) into a real voltage display (with 2 digits after comma)?
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Great idea for X10V!
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