The G1 and Sapphire don't have a current meter on the battery, so the battery levels they show are approximate based on complicated software in the radio and kernel monitoring what is happening in the system. The battery usage UI is also an approximation of power consumption, based on another kind of software monitoring. In this case I would probably trust the latter more than the former -- you'd really want to run your device until the battery is dead to get an idea of the actual impact, it is very likely that you could see the level not drop a whole much (3% is well within the range of noise) and then suddenly go down a lot.
On Thu, Oct 8, 2009 at 10:43 AM, Disconnect <[email protected]> wrote: > > 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. > > > > > > > > > -- Dianne Hackborn Android framework engineer [email protected] Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails. All such questions should be posted on public forums, where I and others can see and answer them. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
