Advanced Charging Controller
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. Regardless of whether the system is rooted with KernelSU/Magisk, the installation is always “systemless”.
PREREQUISITES
- Must read - how to prolong lithium ion batteries lifespan
- Android or KaiOS
- Any root solution (e.g., KernelSU, Magisk, SuperSU, etc)
- Busybox* (only if not rooted with KernelSU or Magisk)
- Non KernelSU/Magisk installs require a way of running
/data/adb/vr25/acc/service.shon boot to initialize acc. - Terminal emulator
- Root text editor (optional)
* A busybox binary can simply be placed in /data/adb/vr25/bin/.
Permissions (0755) are set automatically, as needed.
Precedence: /data/adb/vr25/bin/busybox > KernelSu’s or Magisk’s busybox > system’s busybox
Other executables or static binaries can also be placed in /data/adb/vr25/bin/ (with proper permissions) instead of being installed system-wide.
SETUP/USAGE
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 acc.
It’s a wizard you’ll either love or hate.
If you feel uncomfortable with the command line, skip this section and use a front-end app instead.
Alternatively, you can use a text editor to modify /data/adb/vr25/acc-data/config.txt.
The config file itself has configuration instructions.
Those are the same found in the default configuration section, above.
Terminal Commands
acc --help
PLUGINS
Those are scripts that override functions and some global variables.
They should be placed in /data/adb/vr25/acc-data/plugins/.
Files are sorted and sourced.
Filenames shall not contain spaces.
Hidden files and those without the .sh extension are ignored.
There are also volatile plugins (gone on reboot, useful for debugging): /dev/.vr25/acc/plugins/.
Those override the permanent.
A daemon restart is required to load new/modified plugins.
An alternative to plugins are one-line scripts. Refer to the default configuration section above.
TIPS
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.
Generic
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: apply_on_plug=wireless/voltage_max::9000000.
This may not work on all Pixel devices. There are no negative consequences when it doesn’t.
Export/import Config
Export: acc -s > /sdcard/Download/config.txt
Import: acc -s /sdcard/Download/config.txt
Partial import is supported - meaning, users can share just a portion of the config (e.g., acc -sp curr,volt > file); whoever imports this, gets just those changes.
Override Battery mAh Capacity
An “extended” battery won’t charge fully if the kernel still has the stock charge_full_design value.
Some devices allow that to be modified. If that’s the case for you, use apply_on_boot to set the desired value(s) in /sys/class/power_supply/*/charge_full_design.
Override Broken Temperature Sensor
If your battery’s thermistor always reports a negative value, and charging is very slow or even off, see if the following helps (paste and run):
acc -c d temp_cool; acc -c a ':; for i in */temp_cool */temp_cold; do [ -f $i ] || continue; chown 0:0 $i && chmod 0644 $i && echo "-999" > $i && chown 0444 $i || :; done'
FREQUENTLY ASKED QUESTIONS (FAQ)
How do I report issues?
Open issues on GitHub or contact the developer on Telegram (preferred) or XDA (links below).
Always provide as much information as possible.
Attach /sdcard/Download/acc-logs-*.tgz - 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/article/bu-603-how-to-calibrate-a-smart-battery .
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 device 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.
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/forever-plugged profile: keep capacity within 40-60% (e.g., acc 50 45) and/or voltage around ~3900 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
* https://batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries/
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 device 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.
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.
What’s idle mode, and how do I set it up?
It’s the ability of running off the charger. The battery behaves as if it were physically disconnected from the device. The primary indicator of idle mode is charging current around 0 mA. One can customize idleThreshold (absolute value).
Idle mode is great for extended device use (e.g., GPS navigation, gaming, server). Use it when the charger must be plugged for a long time (or permanently).
IMPORTANT: lithium batteries have the longest lifespan when kept about 40-60% charged (about 3.7-3.9ish Volts). That said, try not to use idle mode above 60% too often.
Not all devices support the “native” idle mode. Hence, variants of “emulated” idle mode are available:
- Limit the charging voltage (requires kernel support) to a value that gets you close to the desired battery level. To avoid false positives, determine the value only after the device has been unplugged for a minute or so.
- Pause/resume charging based on voltage thresholds (e.g., acc 3900 keeps voltage within 3850 and 3900 millivolts).
- Set resume_capacity to (pause_capacity - 1), e.g., acc 50 49.
Notes
- In idle mode, the battery does discharge, although very slowly. The same happens to a battery that is sitting on a shelf.
- In emulated idle mode, the battery tends to hold its charge, since it works as a “passthrough” device. Imagine pouring water into a glass that is already full.
How do I enable “smart charging”?
Configure day and night profiles:
acc -c a ": day profile; at 6:00 \"acc -s pc=75 mcc= mcv=4100; acc -n 'Switched to day profile'\""; acc -c a ": night profile; at 22:00 \"acc -s pc=50 mcc=500 mcv=3900; acc -n 'Switched to night profile'\""