Question about push notifications for apps affect on battery life?

Question

Level 2

207 points

Question about push notifications for apps affect on battery life?

I've noticed that after installing certain "Push Notification Enabled" apps that my iPhone's battery drains very quickly even when said apps aren't running. I've read that if an app makes extensive use of push notifications that it can drain the battery, but I haven't received any notifications from said apps. Does simply having a number of push enabled apps installed drain the battery cause faster than normal battery drain?

I don't really care about the push notifications for many push enabled apps, but I do like to have it enabled for certain ones. Would disabling notifications for all but the apps I use actually save battery life? I would think that since push messages are sent from the app owners server to Apple's push servers to the phone, that disabling notifications on the phone for an app or even deleting the app itself would not prevent the actual data from being pushed to the phone. In other words does disabling notifications (or deleting the app) actually prevent the data from being pushed to the iPhone or does it simply tell the iPhone to ignore the pushed data? The former would not increase battery life while the later would.

iPhone 3GS, iPhone OS 3.1.2

Posted on Dec 28, 2009 8:31 AM

Reply

Answer 1

Morac Author

Level 2

207 points

Feb 8, 2010 1:14 PM in response to Morac

I've learned that it's not the number of apps that use push notification that drains the battery, but the number of apps that actively use it to send messages.

If push is turned on, the battery will drain slightly faster since the phone needs to maintain a constant 3G (or GSM) connection open, but no data is actually sent or received unless you receive a push notification.

In the case of push email, a push notification triggers the mail app to make an outbound IMAP4 connection. Depending on how often you receive email, this can decrease the battery life. If you receive lots of emails every few minutes, using 15 minute fetch will be more battery efficient. If you receive emails every few hours, push is more efficient.

For apps, it doesn't really matter since the apps can't initiate a network connection unless they are running. I'm not sure if app servers constantly sending push notifications when the notification for those apps is turned off drains the battery any faster or not. From what I've read when push notification are turned off for an app, Apple's push servers will tell that app's servers to not perform a push. In other words, Apple won't push app notifications to the phone for apps where notifications are disabled or the app isn't installed.

Reply