Can someone explain what "Always Connected" and "All Day Sync" are?

[Riekopo]

I'm having a hard time figuring out what these two options actually do. I'd like to know for sure because I am someone who needs to maximize my battery life as long as possible on my phone and tablet. My phone is a Nexus 5 and my tablet is a Shield K1. I'd appreciate it if a Fitbit agent could provide a detailed explanation.

[Lillian122]

Great question. I would like to know also. 

[Rich_Laue]

I'll stay with all day sung @Lillian 192 and @Riekopo, some toys is the easiest for me. 

With this feature enables your app will try to sync at intervals throughout the day. My understanding is every 60 minutes. 

My testing of this option seems to confirm this. 

As for always connected, I'm not sure exactly what it does, but it does seem to keep the tracker bonded to the phone better than with the feature off. Making the sync process easier. 

Always connected is optional and on some phones is not needed. My thinking is to try with it disabled, if you have no sync problems, leave it off. If your founding the app has problems sundown are the sync process takes an exceptional long time, try with it turned on.