I need to get statistics about the battery in milliAmpere.
I've already found how to get the battery percentage and voltage but not the current.
There are applications like this that can do it but i wonder how.
Thank you
I believe the only way to get the current is via the logcat. The system will occasionally post it to there so you'll need to go back find the last update for it.
There is no way of measuring current drawn from within the system - this or any other app can only estimate it based on timing information and voltage discharge that the system reports. You are not likely to have anything accurate based on just that though - to have more accurate information you need an accurate device power model.
There is a nice article by the Android framework guys about how the power model is built (also applies to the built-in battery power monitor).
TL;DR
Measurement can be accomplished using a bench power supply or using specialized battery-monitoring tools (such as Monsoon Solution Inc.’s Power Monitor and Power Tool software).
Need to control what components of the device are active (screen on/off/brightness level, cellular/wifi/bluetooth radio, gps, CPU, etc.)
Based on those you build an energy profile similar to the example at the bottom of the page
There are also typical values in the table in the document. Warning: these are highly hardware-dependent
You can then apply the model by monitoring the state of the device and activities of applications (screen state, foreground/background, CPU/network use by an app, etc.)
This is a lot of hard work (sorry about that :) ), but there isn't another good way - it is actually an active research problem...
Related
For a research project I need to measure the power consumption of some functionality. So I would like to measure the power consumption of a method. For example: method computeSomething() needed x microampere-hours. Is this possible? If yes, how?
I tried to measure the remaining battery capacity in microampere-hours and the remaining energy in nanowatt-hours before and after execution with the BatteryManager. But this isn't accurate enough. Is that even possible to do it?
this is what i tried:
mBatteryManager.getLongProperty(BatteryManager.BATTERY_PROPERTY_ENERGY_COUNTER);
EDIT:
for sure it's the emulator which don't consume energy and that's why I get a consumption of 0. Is it possible to simulate power consumption with the android emulator or do I need a real phone?
Here's how I would measure the energy used (because that's what you want and not power).
Shutdown (or don't use) everything I can, including network, cell, USB, etc.
Disable any power saving features on the phone
Log any data you get on the phone's file system (vs through the USB or wireless)
Wrap the program in a large loop that makes its runtime at least a few seconds, perhaps a few minutes
Run the test program you just made many times (>=16 times for statistical significance)
Measure the phone at rest over the same amount of time and collect the energy used.
ANALYSIS: (and you need to do this)
Check on the statistical deviation (std dev) of both your function run and the "at rest" run. If the std dev is large, something else is going on that is using energy.
Find out the resolution of BatteryManager. Just because the field is labeled in nWatts doesn't mean the hardware measures it at that resolution (and it probably doesn't). The people who develop a data structure want that structure to be useful on a lot of hardware and for the foreseeable future. Thus they make the field measure in something very small (e.g. nWatts) even if most hardware can only measure at best, say, in tenth of watts.
If possible, use a hardware interposer between the battery and the phone to measure energy/power directly. This gets around the uncertainty in the implementation of BatteryManager.
Just to be safe, you might also find out how long of an integration window the BatteryManager uses for measuring power. These measurements usually involve a moving window for computing averages.
An emulator isn't going to give you any useful information. Emulators test functionality and little else. Even a rough measure of performance is very iffy.
I've developed a similar App before but is used to evaluate the power consumption of each Application. But as far as I know, the Google's battery static API evaluate power consumption according to each UID, both hardware and software. I think you can find more information by looking into the source code of Android, especially for BatterySipper.java and BatteryStatsHelper.java.
For emulator, Android system uses power_profile.xml as reference to calculate the power consumption. This file is usually modified by manufacturer. Maybe it's not included in emulator.
I am trying to write an application on android and iPhone , my app will use three types of techniques (or maybe more)
GPS , WIFI and Bluetooth , but I am trying to have a deep look on the taxonomy of the battery life on these factors?
Is there any formal study in general that shows a comparison between these factors i.e. I guess they consume battery life in my app
I want my app to be power efficient .
So as I can find a way to reduce the power consummation , or at least use other techniques if available.
It's virtually impossible to accurately get a measurement, have a look at https://stackoverflow.com/a/3377522/3436942 - there's just too many factors - as for a way to reduce consumption - how about turning these off when not in use (create permissions the user agrees to)?
Is there any way to determine what is using power in an app? From what I have found, the most granular I can get is how much power an app itself is using. I want to know what I can do to make my app more efficient in the most empirical way possible as it is easy to justify a change when there are numbers to back it up.
Is there any way to determine what is using power in an app?
You can buy a Qualcomm MDP device and use Trepn to get fairly accurate and detailed power analysis of your app. However, an MDP is expensive.
Otherwise, there is little you can do, simply because current Android production hardware is not instrumented to try to collect this level of information. Even the Battery screen in Settings is mostly just an educated guess.
I'm looking for a list of all the components and their power drainage on an up-to-date smart phone.
Accelerometer, gyroscope, magnetometer, etc.
Display
WiFi
Bluetooth
GPS
CPU
Camera
Microphone
etc.
Preferably in mA so it can be easily compared to the battery's capacity (usually specified in mAh).
The Sensor's power is actually available via the SDK and can also easily figured out for most devices on AndroidFragmentation. However what I'm looking for is comparable data for the other hardware components to consider their efficency.
Bonus: Will a request for less frequent updates of a Sensor decrease energy consumption of the Sensor, as it returns only one value for getPower()?
There are a couple of detailed studies that I am able to find on this.
A study from the USENIX meeting in 2010 which studies various components of a smartphone (except the camera)
Another study from the Hotmobile mobile computing workshop 2013 that has more information on cameras and displays.
Reference 1 especially seems a great starting point.
I'm looking for a list of all the components and their power drainage on an up-to-date smart phone.
That is impossible to answer.
First, different devices will use different varieties of these components, with different power characteristics.
Second, many, if not most, of those components will have no published power statistics, or the specific components themselves may not be knowable without a complete teardown of a device.
Will a request for less frequent updates of a Sensor decrease energy consumption of the Sensor, as it returns only one value for getPower()?
That will depend on the sensor. Some sensors are effectively always "on" (e.g., ambient light sensor), courtesy of the OS, in which case the only incremental power drain for your use of that sensor will be in passing that sensor data to your process. Other sensors might not be regularly used by the OS, meaning that your request for events from that sensor might turn it "on", resulting in power drain from the sensor itself in addition to supplying you with that data.
It would be truly wonderful if all Android devices were instrumented in the way the Qualcomm MDP is, so that we could get fine-grained power detail for our apps and their usage of various components.
There was a Google I/O session on this very subject a few years ago; you can see the video here and slides pdf here.
I know it's against the rules to plug your own startup, but what you're asking sounds exactly like what we're working on.
There's an Android performance monitoring tool called "Little Eye Labs". It shows real-time power consumption of an App as it runs on a phone. It currently only supports CPU, Display, GPS, Wifi and 3G, but you'll be able to get the instantaneous power consumed (in mW) by these components.
/end of plug
Note that there's no real way to get this information directly from a device, so the best you can do is model the phone, gather device resource consumption, and model power usage.
Display is the most power consuming part of the smartphones; accounting for up to 60% of total battery life (Can draw power up to 2W). There is a book called Green IT and its Applications; you can read it online in Google books.
On any modern Android, go to Settings > Battery (sometimes Settings > About > Battery). You should see a graph of power drain over time, as well as how much was used by what component.
Although consumption varies a lot based on usage patterns, in my experience the top consumers are display, radio, and CPU. I have not seen sensors rank high in energy use on any of my devices, in the absence of bugs. The link provided by Yusuf X places game sensors above CPU.
For more information about optimizing battery use on Android, see Reducing the battery impact of apps that downloads content over a smartphone radio and Optimizing Battery Life.
There is an app called PowerTutor that it does some battery consumption measurements for every phone component and for every process. The code is open so you can pick up some ideas from there. Note that this app was optimized for Google's phone, especially for the Nexus One.
I need to perform power measurements for android applications. I tried "powertutor" and it gives the power consumption per every application. Yet, I don't know how accurate its readings are. Does anyone know how accurate it is?
Also, I have used the DDMS to profile the android application. I obtain the processes as memory info about it. Is there a way that i can know the power consumption per process in Android? (some rough estimation?) or is it impossible?
I really need to perform "power" profiling for android applications but I don't know how.
In my academic research for measuring power consumption on Android, we use a power supply hooked up to the phone's battery terminals that outputs the voltage and current to a PC. Measure without the app to get a baseline and then compare against measurements with the app running. It's not extremely accurate, but it's the best way we know how.