Nexus S 4g with latest software patch - build GRJ90 Android 2.3.5
Steps to reproduce
1. Set up mail service with any active Exchange service using default settings.
2. Put phone in Airplane Mode
3. Let the phone sit for an hour or so.
4. View "Battery Usage"
Result - you will see that the primary user of battery is the MAIL service and battery life will have dropped dramatically. Note - you do not see gmail usage this high. So, my question is, why does the MAIL service continue to run/attempt to receive data from the exchange server when the phone is in airplane mode?
This almost completely negates the benefit of having your phone on, but in airplane mode to conserve the battery life when in an area that is outside of cell range (or, gasp, when on a plane!)
Typically, there are "sync intervals" for email accounts. I don't have an exchange email account to load to my Nexus so I can't test this. But when hitting menu from your email inbox, and going to settings, do you see a sync interval? The idea is if your exchange email is syncing every 5 minutes, or has a "sync interval" it's unaware that there is no signal or connection to a network and thus, keeps trying.
I see. It could be a design flaw that I can forward to our device lab for testing. In the meantime, can you turn off "auto push" or uncheck it. Maybe it stops looking for a signal. It's a pretty good assumption that if this only happens when your phone is in airplane mode, then it's repeatedly trying to sync your account even though the radio is off.
Thanks for forwarding it on Tom! I'm testing it again now, airplane mode on but 'sync frequency' for just that mail account set to never.
I'll let you know what it shows in a few hours.
So, I tried to test this but every time I set the mail service to a 'check frequency' of NEVER, it automatically reverts back to Automatic PUSH. So, it seems like there are several bugs with the mail service as it stands right now.