Advanced Charging Controller (ACC)
ACC is an Android software mainly intended for extending battery service life.
In a nutshell, this is achieved through limiting charging current, temperature and voltage.
Any root solution is supported.
The installation is always "systemless", whether or not the system is rooted with Magisk.
Copyright 2017-present, VR25
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see https://www.gnu.org/licenses/.
Always read/reread this reference prior to installing/upgrading this software.
While no cats have been harmed, the author assumes no responsibility for anything that might break due to the use/misuse of it.
To prevent fraud, do NOT mirror any link associated with this project; do NOT share builds (tarballs/zips)! Share official links instead.
ACC manipulates Android low level (kernel) parameters which control the charging circuitry.
The author assumes no responsibility under anything that might break due to the use/misuse of this software.
By choosing to use/misuse it, you agree to do so at your own risk!
- Must read - how to prolong lithium ion batteries lifespan
- Android or Android based OS
- Any root solution (e.g., Magisk)
- Busybox* (only if not rooted with Magisk)
- curl (for acc --upgrade, optional)
- Non-Magisk users can enable acc auto-start by running /data/adb/vr25/acc/service.sh, a copy of, or a link to it - with init.d or an app that emulates it.
- Terminal emulator
- Text editor (optional)
* A busybox binary can simply be placed in /data/adb/bin/.
Permissions (0700) are set automatically, as needed.
Precedence: /data/adb/bin/busybox > Magisk's busybox > system's busybox
Other executables or static binaries can also be placed in /data/adb/bin/ (with proper permissions) instead of being installed system-wide.
QUICK START GUIDE
All commands/actions require root.
Install/upgrade: flash* the zip or use a front-end app (e.g. AccA).
There are two additional ways of upgrading:
acc --upgrade (online) and
acc --flash (zip flasher).
Rebooting after installation/removal is generally unnecessary.
acc (wizard). That's the only command you need to remember.
acc pause_capacity resume_capacity (default
75 70) to set the battery levels at which charging should pause and resume, respectively.
If you come across any issues, refer to the
FAQ sections below.
Read as much as you can prior to reporting issues and/or asking questions.
Oftentimes, solutions/answers will be right before your eyes.
3 are optional because there are default settings.
For details, refer to the
DEFAULT CONFIGURATION section below.
Users are encouraged to try step
2 - to familiarize themselves with the available options.
Settings can be overwhelming. Start with what you understand.
The default configuration has you covered.
Don't ever feel like you have to configure everything. You probably shouldn't anyway - unless you really know what you're doing.
acc --uninstall or flash*
ACC runs in some recovery environments as well.
Unless the zip is flashed again, manual initialization is required.
The initialization command is
BUILDING AND/OR INSTALLING FROM SOURCE
- git, wget, or curl (pick one)
Build Tarballs and Flashable Zips
Download and extract the source code:
git clone https://github.com/VR-25/acc.git
wget https://github.com/VR-25/acc/archive/master.tar.gz -O - | tar -xz
curl -L# https://github.com/VR-25/acc/archive/master.tar.gz | tar -xz
sh build.sh (or double-click
build.bat on Windows 10, if you have Windows subsystem for Linux (with zip) installed)
build.sh automatically sets/corrects
Refer to framework-details.txt for a full list of tasks carried out by it.
To skip generating archives, run the build script with a random argument (e.g. bash build.sh h).
The output files are (in
To update the local source code, run
git pull --force or re-download it (with wget/curl) as described above.
Install from Local Sources or GitHub
sh install-tarball.sh acc installs the tarball (acc*gz) from the script's location.
The archive must be obtained from GitHub: https://github.com/VR-25/acc/archive/$reference.tar.gz ($reference examples: master, dev, v2020.5.20-rc).
sh install.sh installs acc from the extracted source.
sh install-online.sh [-c|--changelog] [-f|--force] [-k|--insecure] [-n|--non-interactive] [%install dir%] [reference] downloads and installs acc from GitHub. e.g.,
sh install-online.sh dev
install-tarball.sh accept a custom parent installation directory (e.g.,
export installDir=/data; sh install.sh /data - this will install acc in /data/acc/).
In addition to the above,
install-online.sh also recognizes a custom parent installation directory supplied as follows:
sh install-online.sh %path% (e.g.,
sh install-online.sh %/data%).
install-online.sh is the
acc --upgrade back-end.
The order of arguments doesn't matter.
The default parent installation directories, in order of priority, are:
/data/data/mattecarra.accapp/files/ (ACC App,
/data/adb/modules/ (Magisk) and
/data/adb/ (other root solutions).
No argument/option is strictly mandatory.
The exception is
--non-interactive for front-end apps.
Unofficially supported front-ends must specify the parent installation directory.
Otherwise, the installer will follow the order above.
--force option to
install-online.sh is meant for re-installation and downgrading.
sh install-online.sh --changelog --non-interactive prints the version code (integer) and changelog URL (string) when an update is available.
In interactive mode, it also asks the user whether they want to download and install the update.
You may also want to read
SETUP/USAGE > Terminal Commands > Exit Codes below.
capacity=(0 60 70 75 false)
temperature=(40 60 90 65)
# Do not edit this in Windows Notepad, ever!
# It replaces LF (Linux/Unix) with CRLF (Windows) line endings.
# As you may have guessed, what is null by default, can be null.
# "language=" is interpreted as "language=en".
# Nullifying values that should not be null causes unexpected behavior.
# However, doing so with "--set var=" restores the default value of "var".
# In other words, for regular users, "--set" is safer than modifying the config file directly.
# Do not feel like you must configure everything!
# Do not change what you don't understand.
# The daemon does not have to be restarted after making changes to this file - unless one of the changes is capacity_freeze2 or charging_switch.
# If charging_switch is changed with --set (e.g., -ss, -s s="...", --set charging_switch="..."), accd is restarted automatically, as needed.
# capacity=(shutdown_capacity cooldown_capacity resume_capacity pause_capacity capacity_freeze2)
# temperature=(cooldown_temp max_temp max_temp_pause shutdown_temp)
# cooldownRatio=(cooldown_charge cooldown_pause)
# cooldownCustom=cooldown_custom=(file raw_value charge_seconds pause_seconds)
# resetBattStats=(reset_batt_stats_on_pause reset_batt_stats_on_unplug)
# chargingSwitch=charging_switch=(ctrl_file1 on off ctrl_file2 on off --)
# applyOnBoot=apply_on_boot=(ctrl_file1::value1::default1 ctrl_file2::value2::default2 ... --exit)
# applyOnPlug=apply_on_plug=(ctrl_file1::value1::default1 ctrl_file2::value2::default2 ...)
# maxChargingCurrent=max_charging_current=([value] ctrl_file1::value::default1 ctrl_file2::value::default2 ...)
# maxChargingVoltage=max_charging_voltage=([value] ctrl_file1::value::default1 ctrl_file2::value::default2 ...) --exit)
# runCmdOnPause=run_cmd_on_pause=(. script)
# loopCmd=loop_cmd=(. script)
# VARIABLE ALIASES/SORTCUTS
# cc cooldown_capacity
# rc resume_capacity
# pc pause_capacity
# cft capacity_freeze2
# sc shutdown_capacity
# ct cooldown_temp
# cch cooldown_charge
# cp cooldown_pause
# mt max_temp
# mtp max_temp_pause
# st shutdown_temp
# ccu cooldown_custom
# cdc cooldown_current
# rbsp reset_batt_stats_on_pause
# rbsu reset_batt_stats_on_unplug
# s charging_switch
# ab apply_on_boot
# ap apply_on_plug
# mcc max_charging_current
# mcv max_charging_voltage
# l lang
# rcp run_cmd_on_pause
# af amp_factor
# vf volt_factor
# lc loop_cmd
# pbim prioritize_batt_idle_mode
# current_workaround currentWorkaround
# COMMAND EXAMPLES
# acc 85 80
# acc -s pc=85 rc=80
# acc --set pause_capacity=85 resume_capacity=80
# acc -s "s=battery/charging_enabled 1 0"
# acc --set "charging_switch=/proc/mtk_battery_cmd/current_cmd 0::0 0::1 /proc/mtk_battery_cmd/en_power_path 1 0" ("::" = " ")
# acc -s -v 3920 (millivolts)
# acc -s -c 500 (milliamps)
# custom config path
# acc /data/acc-night-config.txt 45 43
# acc /data/acc-night-config.txt -s c 500
# accd /data/acc-night-config.txt
# acc -s "ccu=battery/current_now 1450000 100 20"
# acc -s "cooldown_custom=battery/current_now 1450000 100 20"
# acc -s ccu="/sys/devices/virtual/thermal/thermal_zone1/temp 55 50 10"
# acc -s amp_factor=1000
# acc -s volt_factor=1000000
# acc -s mcc=500 mcv="3920 --exit"
# acc -s loop_cmd="echo 0 \\> battery/input_suspend"
# acc -s cooldown_current=500
# acc -s st=60
# FINE, BUT WHAT DOES EACH OF THESE VARIABLES ACTUALLY MEAN?
# configVerCode #
# This is checked during updates to determine whether config should be patched. Do NOT modify.
# shutdown_capacity (sc) #
# When the battery is discharging and its capacity <= sc and phone has been running for 15 minutes or more, acc daemon turns the phone off to reduce the discharge rate and protect the battery from potential damage induced by voltage below the operating range.
# cooldown_capacity (cc) #
# Capacity at which the cooldown cycle starts.
# Cooldown reduces battery stress induced by prolonged exposure to high temperature and high charging voltage.
# It does so through periodically pausing charging for a few seconds (more details below).
# resume_capacity (rc) #
# Capacity at which charging should resume.
# pause_capacity (pc) #
# Capacity at which charging should pause.
# capacity_freeze2 (cft) #
# This prevents Android from getting capacity readings below 2%.
# It's useful on systems that shutdown before the battery is actually empty.
# cooldown_temp (ct) #
# Temperature (°C) at which the cooldown cycle starts.
# Cooldown reduces the battery degradation rate by lowering the device's temperature.
# Refer back to cooldown_capacity for more details.
# max_temp (mt) #
# mtp or max_temp_pause #
# These two work together and are NOT tied to the cooldown cycle.
# On max_temp (°C), charging is paused for max_temp_pause (seconds).
# Unlike the cooldown cycle, which aims at reducing BOTH high temperature and high voltage induced stress - this is ONLY meant specifically for reducing high temperature induced stress.
# Even though both are separate features, this complements the cooldown cycle when environmental temperatures are off the charts.
# shutdown_temp (st) #
# Shutdown the system if battery temperature >= this value.
# cooldown_charge (cch) #
# cooldown_pause (cp) #
# These two dictate the cooldown cycle intervals (seconds).
# When not set, the cycle is disabled.
# Suggested values are cch=50 and cp=10.
# If charging gets a bit slower than desired, try cch=50 and cp=5.
# Note that cooldown_capacity and cooldown_temp can be disabled individually by assigning them values that would never be reached under normal circumstances.
# cooldown_custom (ccu) #
# When cooldown_capacity and/or cooldown_temp don't suit your needs, this comes to the rescue.
# It takes precedence over the regular cooldown settings.
# Refer back the command examples.
# cooldown_current (cdc) #
# Instead of pausing charging periodically during the cooldown phase, limit the max charging current (e.g., to 500 mA)
# reset_batt_stats_on_pause (rbsp) #
# Reset battery stats after pausing charging.
# reset_batt_stats_on_unplug (rbsu) #
# Reset battery stats if the charger has been unplugged for 10 seconds.
# charging_switch (s) #
# If unset, acc cycles through its database and sets the first working switch/group that disables charging.
# If the set switch/group doesn't work, acc unsets chargingSwitch and repeats the above.
# If all switches fail to disable charging, chargingSwitch is unset and acc/d exit with error code 7.
# This automated process can be disabled by appending "--" to "charging_switch=...".
# e.g., acc -s s="battery/charge_enabled 1 0 --"
# charging_switch=milliamps (e.g., 0, 250 or 500) enables current-based charging control.
# For details, refer to the readme's tips section.
# Unlike the original variant, this kind of switch is never unset automatically.
# Appending " --" to it leads to invalid syntax.
# apply_on_boot (ab) #
# Settings to apply on boot or daemon start/restart.
# The --exit flag (refer back to applyOnBoot=...) tells the daemon to stop after applying settings.
# If the --exit flag is not included, default values are restored when the daemon stops.
# apply_on_plug (ap) #
# Settings to apply on plug
# This exists because some /sys files (e.g., current_max) are reset on charger re-plug.
# Default values are restored on unplug and when the daemon stops.
# max_charging_current (mcc) #
# max_charging_voltage (mcv) #
# Only the current/voltage value is to be supplied.
# Control files are automatically selected.
# Refer back to the command examples.
# lang (l) #
# acc language, managed with "acc --set --lang" (acc -s l).
# run_cmd_on_pause (rcp) #
# Run commands* after pausing charging.
# * Usually a script ("sh some_file" or ". some_file")
# amp_factor (af) #
# volt_factor (vf) #
# Unit multiplier for conversion (e.g., 1V = 1000000 Microvolts)
# ACC can automatically determine the units, but the mechanism is not 100% foolproof.
# e.g., if the input current is too low, the unit is miscalculated.
# This issue is rare, though.
# Leave these properties alone if everything is running fine.
# loop_cmd (lc) #
# This is meant for extending accd's functionality.
# It is periodically executed by is_charging() - which is called regularly, within the main accd loop.
# The boolean isCharging is available.
# Refer back to COMMAND EXAMPLES.
# prioritize_batt_idle_mode (pbim) #
# If enabled charging switches that support battery idle mode take precedence.
# This is disabled by default due to issues on Samsung (store_mode) and other devices.
# currentWorkaround (current_workaround) #
# Only use current control files whose paths match "batt" (default: false).
# This is necessary only if the current limit affects both input and charging current values.
# A reboot is required after changing this.
As the default configuration (above) suggests, ACC is designed to run out of the box, with little to no customization/intervention.
The only command you have to remember is
It's a wizard you'll either love or hate.
If you feel uncomfortable with the command line, skip this section and use the ACC App to manage ACC.
Alternatively, you can use a
text editor to modify
The config file itself has configuration instructions.
These instructions are the same found in the
DEFAULT CONFIG section, above.
accd Start/restart accd
accd. Stop acc/daemon
accd, Print acc/daemon status (running or not)
acc [pause_capacity [resume_capacity, default: pause_capacity - 5]]
acc 75 70
acc 80 (resume_capacity defaults to 80 - 5)
acc [options] [args] Refer to the list of options below
acca [options] [args] acc optimized for front-ends
A custom config path can be specified as first parameter.
If the file doesn't exist, the current config is cloned.
acc /data/acc-night-config.txt --set pause_capacity=45 resume_capacity=43
acc /data/acc-night-config.txt --set --current 500
-c|--config [editor] [editor_opts] Edit config (default editor: nano/vim/vi)
acc -c (edit w/ nano/vim/vi)
acc -c less
acc -c cat
-d|--disable [#%, #s, #m or #h (optional)] Disable charging
acc -d 70% (do not recharge until capacity <= 70%)
acc -d 1h (do not recharge until 1 hour has passed)
-D|--daemon Print daemon status, (and if running) version and PID
e.g., acc -D (alias: "accd,")
-D|--daemon [start|stop|restart] Manage daemon
acc -D start (alias: accd)
acc -D restart (alias: accd)
accd -D stop (alias: "accd.")
-e|--enable [#%, #s, #m or #h (optional)] Enable charging
acc -e 75% (recharge to 75%)
acc -e 30m (recharge for 30 minutes)
-f|--force|--full [capacity] Charge once to a given capacity (default: 100%), without restrictions
acc -f 95 (charge to 95%)
acc -f (charge to 100%)
Note: if the desired % is less than pause_capacity, use acc -e #%
-F|--flash ["zip_file"] Flash any zip files whose update-binary is a shell script
acc -F (lauches a zip flashing wizard)
acc -F "file1" "file2" "fileN" ... (install multiple zips)
acc -F "/sdcard/Documents/vr25/Magisk-v20.0(20000).zip"
-i|--info [case insentive egrep regex (default: ".")] Show battery info
acc -i volt
acc -i 'volt\|curr'
-l|--log [-a|--acc] [editor] [editor_opts] Print/edit accd log (default) or acc log (-a|--acc)
acc -l (same as acc -l less)
acc -l rm
acc -l -a cat
acc -l grep ': ' (show explicit errors only)
-la Same as -l -a
-l|--log -e|--export Export all logs to /sdcard/Documents/vr25/acc/logs/acc-logs-$deviceName.tar.bz2
e.g., acc -l -e
-le Same as -l -e
-r|--readme [editor] [editor_opts] Print/edit README.md
acc -r (same as acc -r less)
acc -r cat
-R|--resetbs Reset battery stats
e.g., acc -R
-s|--set Print current config
e.g., acc -s
-s|--set prop1=value "prop2=value1 value2" Set [multiple] properties
acc -s charging_switch=
acc -s pause_capacity=60 resume_capacity=55 (shortcuts: acc -s pc=60 rc=55, acc 60 55)
acc -s "charging_switch=battery/charging_enabled 1 0" resume_capacity=55 pause_capacity=60
Note: all properties have short aliases for faster typing; run "acc -c cat" to see these
-s|--set c|--current [milliamps|-] Set/print/restore_default max charging current (range: 0-9999 Milliamps)
acc -s c (print current limit)
acc -s c 500 (set)
acc -s c - (restore default)
-sc [milliamps|-] Same as above
-s|--set l|--lang Change language
e.g., acc -s l
-sl Same as above
-s|--set d|--print-default [egrep regex (default: ".")] Print default config without blank lines
acc -s d (print entire defaul config)
acc -s d cap (print only entries matching "cap")
-sd [egrep regex (default: ".")] Same as above
-s|--set p|--print [egrep regex (default: ".")] Print current config without blank lines (refer to previous examples)
-sp [egrep regex (default: ".")] Same as above
-s|--set r|--reset Restore default config
acc -s r
rm /sdcard/Documents/vr25/acc/config.txt (failsafe)
-sr Same as above
-s|--set s|charging_switch Enforce a specific charging switch
e.g., acc -s s
-ss Same as above
-s|--set s:|chargingSwitch: List known charging switches
e.g., acc -s s:
-ss: Same as above
-s|--set v|--voltage [millivolts|-] [--exit] Set/print/restore_default max charging voltage (range: 3700-4200 Millivolts)
acc -s v (print)
acc -s v 3920 (set)
acc -s v - (restore default)
acc -s v 3920 --exit (stop the daemon after applying settings)
-sv [millivolts|-] [--exit] Same as above
-t|--test [ctrl_file1 on off [ctrl_file2 on off]] Test custom charging switches
acc -t battery/charging_enabled 1 0
acc -t /proc/mtk_battery_cmd/current_cmd 0::0 0::1 /proc/mtk_battery_cmd/en_power_path 1 0 ("::" is a placeholder for " ")
-t|--test [file] Test charging switches from a file (default: /dev/.vr25/acc/ch-switches)
This will also report whether "battery idle" mode is supported
acc -t (test known switches)
acc -t /sdcard/experimental_switches.txt (test custom/foreign switches)
-T|--logtail Monitor accd log (tail -F)
e.g., acc -T
-u|--upgrade [-c|--changelog] [-f|--force] [-k|--insecure] [-n|--non-interactive] Online upgrade/downgrade (requires curl)
acc -u dev (upgrade to the latest dev version)
acc -u (latest version from the current branch)
acc -u master^1 -f (previous stable release)
acc -u -f dev^2 (two dev versions below the latest dev)
acc -u v2020.4.8-beta --force (force upgrade/downgrade to v2020.4.8-beta)
acc -u -c -n (if update is available, prints version code (integer) and changelog link)
acc -u -c (same as above, but with install prompt)
-U|--uninstall Completelly remove acc and AccA
e.g., acc -U
-v|--version Print acc version and version code
e.g., acc -v
-w#|--watch# Monitor battery uevent
acc -w (update info every 3 seconds)
acc -w0.5 (update info every half a second)
acc -w0 (no extra delay)
1. False or general failure
2. Incorrect command syntax
3. Missing busybox binary
4. Not running as root
5. Update available ("--upgrade")
6. No update available ("--upgrade")
7. Failed to disable charging
8. Daemon already running ("--daemon start")
9. Daemon not running ("--daemon" and "--daemon stop")
10. "--test" failed
11. Current (mA) out of range
12. Initialization failed
13. Failed to lock /dev/.vr25/acc/acc.lock
Logs are exported automatically ("--log --export") on exit codes 1, 2, 7 and 10.
Commands can be chained for extended functionality.
e.g., charge for 30 minutes, pause charging for 6 hours, charge to 85% and restart the daemon
acc -e 30m && acc -d 6h && acc -e 85 && accd
acc -s pc=45 rc=43 mcc=500 mcv=3920
This keeps battery capacity between 43-45%, limits charging current to 500 mA and voltage to 3920 millivolts.
It's great for nighttime and "forever-plugged".
Refer to acc -r (or --readme) for the full documentation (recommended)
NOTES/TIPS FOR FRONT-END DEVELOPERS
These are optimized for front-ends - guaranteed to be readily available after installation/initialization and significantly faster than regular acc commands.
It may be best to use long options over short equivalents - e.g.,
/dev/.vr25/acc/acca --set charging_switch= instead of
/dev/.vr25/acc/acca -s s=.
This makes code more readable (less cryptic).
Include provided descriptions for ACC features/settings in your app(s).
Provide additional information (trusted) where appropriate.
Explain settings/concepts as clearly and with as few words as possible.
Take advantage of exit codes.
Refer back to
SETUP/USAGE > Terminal Commands > Exit Codes.
1) Check whether ACC is installed (exit code 0)
2) Download the installer (https://raw.githubusercontent.com/VR-25/acc/master/install-online.sh)
curl -#LO <URL>
wget -O install-online.sh <URL>
3) Run "sh install-online.sh" (installation progress is shown)
Refer back to the
BUILDING AND/OR INSTALLING FROM SOURCE section.
Officially Supported Front-ends
- ACC App, a.k.a., AccA (installDir=/data/data/mattecarra.accapp/files/acc/)
[Samsung] Charging Always Stops at 70% Capacity
This is a device-specific issue (by design?).
It's caused by the store_mode charging control file.
Switch to batt_slate_mode to prevent it.
### Charging Switch below for details on that.
Battery Capacity (% Level) Doesn't Seem Right
When Android's battery level differs from that of the kernel, ACC daemon automatically syncs it by stopping the battery service and feeding it the real value every few seconds.
Pixel devices are known for having battery level discrepancies for the longest time.
If your device shuts down before the battery is actually empty, capacity_freeze2 may help.
Refer to the
default configuration section above for details.
Battery Idle Mode On OnePlus 7/8 Variants (Possibly 5 and 6 Too)
Recent/custom kernels (e.g., Kirisakura) support battery idle mode.
However, at the time of this writing, the feature is not production quality.
ACC has custom code to cover the pitfalls, though.
To configure idle mode, simply run
acc -ss and pick
battery/op_disable_charge 0 1 or
battery/op_disable_charge 0 1 battery/input_suspend 0 0.
While uncommon, it may happen.
It's assumed that you already know at least one of the following: temporary disable root (e.g., Magisk), disable Magisk modules or enable Magisk core-only mode.
Most of the time, though, it's just a matter of plugging the phone before turning it on.
Battery level must be below pause_capacity.
Once booted, one can run
acc --uninstall (or
acc -U) to remove ACC.
From recovery, one can flash
/sdcard/Documents/vr25/acc/acc-uninstaller.zip or run
mount /system; /data/adb/vr25/acc/uninstall.sh.
By default, ACC uses whichever charging switch works.
However, things don't always go well.
Some switches are unreliable under certain conditions (e.g., while display is off).
Others hold a wakelock.
This causes fast battery drain when charging is paused and the device remains plugged.
Charging keeps being re-enabled by the system, seconds after acc daemon disables it.
As a result, the battery eventually charges to 100% capacity, regardless of pause_capacity.
High CPU load (drains battery) was also reported.
In the worst case scenario, the battery status is reported as
discharging, while it's actually
In such situations, one has to enforce a switch that works as expected.
Here's how to do it:
acc --test (or
acc -t) to see which switches work.
acc --set charging_switch (or
acc -ss) to enforce a working switch.
- Test the reliability of the set switch. If it doesn't work properly, try another.
Since not everyone is tech savvy, ACC daemon automatically applies certain settings for specific devices (e.g., MediaTek, OnePlus, Razer) to minimize charging switch issues.
These are are in
Note: as part of the output of
acc -ss and
acc -ss:, you may see plain numbers alone or in addition to charging switches.
These are presets the
current-based charging control feature.
For details, refer to
Tips section below.
Custom Max Charging Voltage And Current Limits
Unfortunately, not all kernels support these features.
While custom current limits are supported by most (at least to some degree), voltage tweaking support is exceptionally rare.
That said, the existence of potential voltage/current control file doesn't necessarily mean these are writable* or the features, supported.
* Root is not enough.
Kernel level permissions forbid write access to certain interfaces.
Sometimes, restoring the default current may not work without a system reboot.
A workaround is setting the default max current value or any arbitrary high number (e.g., 9000 mA).
Don't worry about frying things.
The phone will only draw the max it can take.
WARNING: limiting voltage causes battery state of charge (SoC) deviation on some devices.
The battery management system self-calibrates constantly, though.
Thus, as soon as the default voltage limit is restored, it'll start "fixing" itself.
Limiting current, on the other hand, has been found to be universally safe.
Some devices do not support just any current value, though.
That's not to say out-of-range values cause issues.
These are simply ignored.
Volatile logs (gone on reboot) are stored in
/dev/.vr25/acc/, persistent logs -
acc -le exports all acc logs, plus Magisk's and extras to
The logs do not contain any personal information and are never automatically sent to the developer.
Automatic exporting (local) happens under specific conditions (refer back to
SETUP/USAGE > Terminal Commands > Exit Codes).
Restore Default Config
This can save you a lot of time and grief.
acc --set --reset,
acc -sr or
rm /sdcard/Documents/vr25/acc/config.txt (failsafe)
At least one of the following may be the cause:
- Charging current and/or voltage limits
- Cooldown cycle (non optimal charge/pause ratio, try 50/10 or 50/5)
- Troublesome charging switch (refer back to
TROUBLESHOOTING > Charging Switch)
- Weak adapter and/or power cord
POWER SUPPLY LOG (HELP NEEDED)
acc -le and upload
/sdcard/Documents/vr25/acc/logs/power_supply-*.log to my dropbox (no account/sign-up required).
This file contains invaluable power supply information, such as battery details and available charging control files.
A public database is being built for mutual benefit.
Your cooperation is greatly appreciated.
- Name: phone brand and/or model (e.g., 1+7pro, Moto Z Play)
- Email: random/fake
See current submissions here.
Currently Supported Languages and Translation Statuses
- English (en): complete
- Portuguese, Portugal (pt-PT): partial
- Simplified Chinese (zh-rCN): partial
Start with copies of acc/strings.sh and README.md.
Modify the header of strings.sh to reflect the translation (e.g., # Español (es)).
Anyone is free and encouraged to open translation pull requests.
Alternatively, a compressed archive of translated
README.md files can be sent to the developer via Telegram (link below).
acc -sl (--set --lang): language switching wizard
Current-based Charging Control (EXPERIMENTAL)
Enabled by setting charging_switch=milliamps (e.g.,
acc -s s=0,
acc -s s=250 or
acc -ss (wizard)).
Essentially, this turns current control files into [pseudo] charging switches.
A common positive side effect of this is [pseudo] idle mode - i.e., the battery may work just as a power buffer.
Note: depending on the kernel - at
pause_capacity, the charging status may either change ("discharging" or "not charging") or remain still ("charging" - not an issue).
If it changes intermittently, the current is too low; increment it until the issue goes away.
Emulate battery idle mode with a voltage limit:
acc -s pc=101 rc=0 mcv=3920.
The first two arguments disable the regular charging pause/resume functionality.
The last sets a voltage limit that will dictate how much the battery should charge.
The battery enters a [pseudo] idle mode when its voltage peaks.
Essentially, it works as a power buffer.
Limiting the charging current to 0-250 mA or so (e.g.,
acc -sc 0) may produce the same effect.
acc -sc - restores the default limit.
Force fast charge:
appy_on_boot="/sys/kernel/fast_charge/force_fast_charge::1::0 usb/boost_current::1::0 charger/boost_current::1::0"
Google Pixel Devices
Force fast wireless charging with third party wireless chargers that are supposed to charge the battery faster:
This may not work on all Pixel devices.
There are no negative consequences when it doesn't.
Always Limit the Charging Current If Your Battery is Old and/or Tends to Discharge Too Fast
This extends the battery's lifespan and may even reduce its discharge rate.
750-1000mA is a good range for regular use.
500mA is a comfortable minimum - and also very compatible.
If your device does not support custom current limits, use a dedicated ("slow") power adapter.
FREQUENTLY ASKED QUESTIONS (FAQ)
How do I report issues?
Open issues on GitHub or contact the developer on Facebook, Telegram (preferred) or XDA (links below).
Always provide as much information as possible.
/sdcard/Documents/vr25/acc/logs/acc-logs-*tar.bz2 - generated by
acc -le right after the problem occurs.
Refer back to
TROUBLESHOOTING > Diagnostics/Logs for additional details.
Why won't you support my device? I've been waiting for ages!
Firstly, have some extra patience!
Secondly, several systems don't have intuitive charging control files; I have to dig deeper - and oftentimes, improvise; this takes time and effort.
Lastly, some systems don't support custom charging control at all; in such cases, you have to keep trying different kernels and uploading the respective power supply logs.
Refer back to
POWER SUPPLY LOGS (HELP NEEDED).
Why, when and how should I calibrate the battery manager?
With modern battery management systems, that's generally unnecessary.
However, if your battery is underperforming, you may want to try the procedure described at https://batteryuniversity.com/index.php/learn/article/battery_calibration .
I set voltage to 4080 mV and that corresponds to just about 75% charge.
But is it typically safer to let charging keep running, or to have the circuits turn on and shut off between defined percentage levels repeatedly?
It's not much about which method is safer.
It's specifically about electron stability: optimizing the pressure (voltage) and current flow.
As long as you don't set a voltage limit higher than 4200 mV and don't leave the phone plugged in for extended periods of time, you're good with that limitation alone.
Otherwise, the other option is actually more beneficial - since it mitigates high pressure (voltage) exposure/time to a greater extent.
If you use both, simultaneously - you get the best of both worlds.
On top of that, if you enable the cooldown cycle, it'll give you even more benefits.
Anyway, while the battery is happy in the 3700-4100 mV range, the optimal voltage for [the greatest] longevity is said* to be ~3920 mV.
If you're leaving your phone plugged in for extended periods of time, that's the voltage limit to aim for.
Ever wondered why lithium ion batteries aren't sold fully charged? They're usually ~40-60% charged. Why is that?
Keeping a battery fully drained, almost fully drained or 70%+ charged for a long times, leads to significant (permanent) capacity loss
Putting it all together in practice...
Night/heavy-duty profile: keep capacity within 40-60% and/or voltage around ~3920 mV
Day/regular profile: max capacity: 75-80% and/or voltage no higher than 4100 mV
Travel profile: capacity up to 95% and/or voltage no higher than 4200 mV
I don't really understand what the "-f|--force|--full [capacity]" is meant for.
Consider the following situation:
You're almost late for an important event.
You recall that I stole your power bank and sold it on Ebay.
You need your phone and a good battery backup.
The event will take the whole day and you won't have access to an external power supply in the middle of nowhere.
You need your battery charged fast and as much as possible.
However, you don't want to modify ACC config nor manually stop/restart the daemon.
It's a standalone program: Daily Job Scheduler.
As the name suggests, it's meant for scheduling "jobs" - in this context, acc profiles/settings.
Underneath, it runs commands/scripts at specified times - either once, daily and/or on boot.
Do I have to install/upgrade both ACC and AccA?
To really get out of this dilemma, you have to understand what ACC and AccA essentially are.
ACC is a Android program that controls charging.
It can be installed as an app (e.g., AccA) module, Magisk module or standalone software. Its installer determines the installation path/variant. The user is given the power to override that.
A plain text file holds the program's configuration. It can be edited with any root text editor.
ACC has a command line interface (CLI) - which in essence is a set of Application Programing Interfaces (APIs). The main purpose of a CLI/API is making difficult tasks ordinary.
AccA is a graphical user interface (GUI) for the ACC command line. The main purpose of a GUI is making ordinary tasks simpler.
AccA ships with a version of ACC that is automatically installed when the app is first launched.
That said, it should be pretty obvious that ACC is like a fully autonomous car that also happens to have a steering wheel and other controls for a regular driver to hit a tree.
Think of AccA as a robotic driver that often prefers hitting people over trees.
Due to extenuating circumstances, that robot may not be upgraded as frequently as the car.
Upgrading the car regularly makes the driver happier - even though I doubt it has any emotion to speak of.
The back-end can be upgraded by flashing the latest ACC zip.
However, unless you have a good reason to do so, don't fix what's not broken.
Does acc work also when Android is off?
No, but this possibility is being explored.
Currently, it does work in recovery mode, though.
I have this wakelock as soon as charging is disabled. How do I deal with it?
The best solution is enforcing a charging switch that doesn't trigger a wakelock.
Refer back to
TROUBLESHOOTING > Charging Switch.
A common workaround is having
resume_capacity = pause_capacity - 1. e.g., resume_capacity=74, pause_capacity=75.
- 500 mA preset for charging_switch.
acc [pause_capacity [resume_capacity, default: pause_capacity - 5]], e.g., acc 80 (resume_capacity defaults to 80 - 5)
- Enhanced current-based charging control (still experimental, but should be more stable now).
- General fixes and optimizations
- Updated documentation.
Release note: those using current-based charging control should reboot after the upgrade.
- Additional charging switches
- Current control enhancements
acc -sr (reset config command).
- General fixes & optimizations
- Improved power supply logger.
- Updated translations.
If cooldown_current is set or current-based charging control is enabled (e.g., charging_switch=0), reboot after upgrading.
If custom charging current limit is set, reboot after upgrading then reapply the limit (e.g., acc -sc 1000).
Nexus 7 users, I'm yet to find charging and current control files for this family of devices.
The power supply logs contain nothing relevant.
battery/op_disable_charge 0 1 charging switch for OnePlus devices.
Enforce control files mode 0644, so that other processes cannot reset/override changes made by acc.
Fixed current control issues.
For details, refer to
config.txt > current_workaround or
readme > default config > current_workaround.
Release note: those who have current-related settings must reboot after upgrading, then reapply those settings manually (e.g.,
acc -sc 1800).