I was going to post basically the same thing but his 3%-after-2-hours measurement doesn't really agree with that.
On Thu, Oct 8, 2009 at 1:40 PM, RichardC <[email protected]> wrote: > > By running your background task every 2secs your are basically keeping > the phone permanently on. Even though your app is not using much CPU > it has to wake the phone from any sleep state every 2secs. So it > either will not allow the phone to sleep or mostly keep it awake. > Waking the phone will power up all hardware devices that are needed > from any low power state they are currently in and reset their sleep > timeouts. > > Basically any background tasks (something not associated with the > current foreground activity the user is interacting with) should only > wake up very infrequently (say greater then 60mins). > > Also are you sleeping in your background task or using an alarm > event. Sleeping is bad ... see lots of posts by Dianne Hackborn on > this very subject. > > -- > RichardC > > On Oct 8, 5:55 pm, dadical <[email protected]> wrote: >> I have an application that runs a background service. This background >> service wakes and runs once every 2 seconds. The background service >> registers as a listener with the orientation sensor with the lowest >> possible rate of event delivery (application). When my service thread >> wakes it uses the latest value delivered by the sensor events, so >> there is no heavy-weight processing being done on the sensor thread. >> Furthermore, the background thread is doing very light processing when >> it wakes. >> >> I've done tests that show that my background thread poses very minor >> power overhead, somewhere around 3%. The test was basically: charge >> to 100%, leave phone on for two hours with service running, record >> battery level. Repeat with service off and compare. >> >> However "Battery Usage" of my application is listed as some insanely >> high value (e.g., 40%). Over the same two hour period of the test, >> CPU usage was less than 3 seconds. >> >> What does "battery usage" mean? In my case, it clearly isn't an >> indication of "battery drain", but that is what the stat seems to >> imply. > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -~----------~----~----~----~------~----~------~--~---
