I have checked the file. The app should work, since the file exists. But I don't understand why it's "0", even after I deleted your app and did a restart.I don't know the reason(I don't think this is kernel dependent), but just check this file(whether it exists): /sys/class/power_supply/battery/charging_enabled
It should be 1 by default. And when it reaches the limit, the value is made 0 by the app.