More autonomy: Calibrating the battery on Android

A common complaint from users of Android is that in many cases, the battery life may fall over time, making a device that could stand before a full day of heavy use on a single charge to go ask for water in the afternoon, for example. Whereas the autonomy of most devices with Android is not the best, no additional reduction can be really disturbing.

This reduction can start small and increased with time, symptoms can be confused with a battery ages, but the actual cause has nothing to do with the battery health.

Android constantly monitors battery usage, saving the information in the file "/ data / system / batterystats.bin." The big problem is that over time, after many partial charges and discharges, it is common that the system moves to blur, stopping the charge before the battery is fully charged. With this, the system may assume that a load of only 60 or 70% equivalent to a full charge, making it the autonomy to fall by a third or more. This problem is especially common in or Milestone Milestone 2, but can also be found on other devices, regardless of the version of Android in use, especially if you have a habit of switching between different ROMs.

The main symptom is the meter going to fall very fast to an intermediate level to a low battery warning, remained stable at 60% of the 100 and then falling rapidly to 20%.

Fortunately, this is a simple problem to solve, since you have root access.

Start by plugging the charger and let it charge completely. The next step is to delete the file statistics, making the system "forget" the incorrect status of the battery. If you have the Root Explorer installed, you can simply open the manager and delete the file "/ data / system / batterystats.bin"

Otherwise, you can delete it using the Battery Calibration, a free utility available in the Market (the "Battery Calibration" serves precisely to delete the file). Do not worry, this is just a log file, which will be recreated on next boot.

Deleted the file, unplug it and connect it (off) to boot. You will see the battery indicator shows 100%:

Keeping the device while connected to the charger, disconnect the battery:

This will cause it to reset itself and show a battery icon with a question mark:

Once it appears, replace the battery (with the power on) and after a few seconds the meter will rise to 60%:

From there, continue charging until the battery actually reach a maximum (time may vary depending on how the statistics were deregulated system). Wait for the meter to reach 100% and leave 15 minutes to more secure and you will again have the original autonomy.

If you are a lot of time using the device with reduced autonomy, the increase may be surprising.

This recipe is simple to calibrate the battery, but there are many other possible procedures, which may work better on other devices. A common alternative is to leave the phone on until it shut down for lack of energy, let it fully charge while off, delete the batterystats.bin (or use the "Battery stats wipe" the nandroid) and then repeat the process. In any case, the basic idea is to clear the statistics and re-train the system to return it to use the full capacity of the battery.