7 ms·

If I leave an app running in the background that keeps the net connection open on my Nexus One, the battery goes from 100 to 0 in about 5 hours.

by tumult 17y ago

orangecat 17y ago
I'd bet that app was poorly written and doing something else in the background. An app that is just listening for data from an open connection should be using roughly zero CPU. But we'll try science; I've signed into AIM on my Nexus One and left it running in the background. The battery is at 81% now, I'll report back in an hour.
- kreneskyp 17y ago
  If you keep a connection open it drains battery life because the chip can't power down.
  - theBobMcCormick 17y ago
    Sort of. In tumult's case he's got a connection that's actively downloading data and playing music. I would assume that'd keep the radio chipset (either wifi or cell, whichever he's using) and the CPU both from being able to switch to a lower power standby mode. However, you can have an open but idle connection open in the background with only minimal battery drain. That's how pretty much every kind of push notification or IM system works, even on cell phones.
- orangecat 17y ago
  77% after an hour.
  - tumult 17y ago
    Sign in with the connection currently using WiFi instead of GPRS/3G, and it will keep the WiFi hardware on, which is what kills it. There is no way for a normal user to know that they need to open new, persistent connections over a connection type that uses the cellular modem instead of the WiFi. And Android defaults to using WiFi for new connections if the WiFi hardware is powered on and connected to a network. The best way to save battery on an Android phone is to turn off WiFi unless you need it at some point during the day. iPhone will stop attempting to do push notifications and the background Apple apps will disconnect if the only available connection is WiFi. I'd also like to point out that "I bet the app was poorly written" is exactly the situation Apple is currently avoiding until they are confident they have a reasonable technical solution to it.
    - orangecat 17y ago
      I was signed in using WiFi, and I normally have WiFi enabled all the time and get over 24 hours of battery life. Maybe some wireless chipsets suck too much power, but it doesn't appear to be a problem on the N1.
      - tumult 17y ago
        Maybe we're doing something different, but I cannot get my Nexus One to stay alive for longer than 5 hours with an active net connection. It if it's a low-traffic connection (calm IRC channels, occasional email polling) it will last a day (same with my G1) but streaming radio, etc will leave it dead in a long afternoon.
        theBobMcCormick 17y ago
        Ah.. Streaming radio. By active net connection I thought you meant email polling, IM, etc. Playing streaming video will kill the battery pretty decently, but IMHO that seems fair. Your keeping the radio pretty busy, the audio hardware, the cpu, etc. I'd actually like to hear from an iPhone user whether they can run Pandora or Last.fm for 5 hours straight without killing their battery either.
        tumult 17y ago
        I'm an iPhone user as well, and it also kills the iPhone. the point was that on iPhone, 3rd party apps are not given the opportunity to do this without the user being aware (because it's in the foreground.) i've had a runaway android app kill my phone after it screwed up and started devouring resources in the background while it was in my pocket.
        theBobMcCormick 17y ago
        The user would have to be aware of streaming audio. Also, as stated elsewhere in this thread, apps don't normally run in the background on Android either. I'm curious what app you believe killed your battery life in the background? That sounds... unusual.
- stcredzero 17y ago
  I'd bet that app was poorly written and doing something else in the background. An app that is just listening for data from an open connection should be using roughly zero CPU. It would be too much work to vet every app for good concurrent programming. It's a much better idea to disallow it and add an API with resource controls later. This is the only way to protect users from resource hog apps.
buster 17y ago
Well, i have atleast running: Facebook, twitter, rss aggregation, gmail and k-9mail imap idle, gtalk plus weather and my phone is at around 30% end of a normal day with a few calls and around 2hrs rss reading on my way to/from work. Only one day battery life is quite sad compared to featurephones but i'd say it's normal for the smartphone of today. Oh, and i have gps/wifi turned on that day. Android 2.1 admittedly has some big improvements around that, as on my G1 wifi/gps made a much bigger difference. According to the battery stats the display is draining by far the most power anyway.
- gte910h 17y ago
  My iphone runs ~2.5 days without a charge...
deleted 17y ago
[deleted]

If I leave an app running in the background that keeps the net connection open on my Nexus One, the battery goes from 100 to 0 in about 5 hours.

by tumult 17y ago

If I leave an app running in the background that keeps the net connection open on my Nexus One, the battery goes from 100 to 0 in about 5 hours.

orangecat 17y ago

I'd bet that app was poorly written and doing something else in the background. An app that is just listening for data from an open connection should be using roughly zero CPU. But we'll try science; I've signed into AIM on my Nexus One and left it running in the background. The battery is at 81% now, I'll report back in an hour.

kreneskyp 17y ago
If you keep a connection open it drains battery life because the chip can't power down.
- theBobMcCormick 17y ago
  Sort of. In tumult's case he's got a connection that's actively downloading data and playing music. I would assume that'd keep the radio chipset (either wifi or cell, whichever he's using) and the CPU both from being able to switch to a lower power standby mode. However, you can have an open but idle connection open in the background with only minimal battery drain. That's how pretty much every kind of push notification or IM system works, even on cell phones.
orangecat 17y ago
77% after an hour.
- tumult 17y ago
  Sign in with the connection currently using WiFi instead of GPRS/3G, and it will keep the WiFi hardware on, which is what kills it. There is no way for a normal user to know that they need to open new, persistent connections over a connection type that uses the cellular modem instead of the WiFi. And Android defaults to using WiFi for new connections if the WiFi hardware is powered on and connected to a network. The best way to save battery on an Android phone is to turn off WiFi unless you need it at some point during the day. iPhone will stop attempting to do push notifications and the background Apple apps will disconnect if the only available connection is WiFi. I'd also like to point out that "I bet the app was poorly written" is exactly the situation Apple is currently avoiding until they are confident they have a reasonable technical solution to it.
  - orangecat 17y ago
    I was signed in using WiFi, and I normally have WiFi enabled all the time and get over 24 hours of battery life. Maybe some wireless chipsets suck too much power, but it doesn't appear to be a problem on the N1.
    - tumult 17y ago
      Maybe we're doing something different, but I cannot get my Nexus One to stay alive for longer than 5 hours with an active net connection. It if it's a low-traffic connection (calm IRC channels, occasional email polling) it will last a day (same with my G1) but streaming radio, etc will leave it dead in a long afternoon.
      - theBobMcCormick 17y ago
        Ah.. Streaming radio. By active net connection I thought you meant email polling, IM, etc. Playing streaming video will kill the battery pretty decently, but IMHO that seems fair. Your keeping the radio pretty busy, the audio hardware, the cpu, etc. I'd actually like to hear from an iPhone user whether they can run Pandora or Last.fm for 5 hours straight without killing their battery either.
        tumult 17y ago
        I'm an iPhone user as well, and it also kills the iPhone. the point was that on iPhone, 3rd party apps are not given the opportunity to do this without the user being aware (because it's in the foreground.) i've had a runaway android app kill my phone after it screwed up and started devouring resources in the background while it was in my pocket.
        theBobMcCormick 17y ago
        The user would have to be aware of streaming audio. Also, as stated elsewhere in this thread, apps don't normally run in the background on Android either. I'm curious what app you believe killed your battery life in the background? That sounds... unusual.
stcredzero 17y ago
I'd bet that app was poorly written and doing something else in the background. An app that is just listening for data from an open connection should be using roughly zero CPU. It would be too much work to vet every app for good concurrent programming. It's a much better idea to disallow it and add an API with resource controls later. This is the only way to protect users from resource hog apps.

buster 17y ago

Well, i have atleast running: Facebook, twitter, rss aggregation, gmail and k-9mail imap idle, gtalk plus weather and my phone is at around 30% end of a normal day with a few calls and around 2hrs rss reading on my way to/from work. Only one day battery life is quite sad compared to featurephones but i'd say it's normal for the smartphone of today. Oh, and i have gps/wifi turned on that day. Android 2.1 admittedly has some big improvements around that, as on my G1 wifi/gps made a much bigger difference. According to the battery stats the display is draining by far the most power anyway.

gte910h 17y ago
My iphone runs ~2.5 days without a charge...

deleted 17y ago

[deleted]