I have a handful of email accounts that come to my iphone...some hardly ever get used. If I change the ones I don't use very often to fetch will it use less battery than having them all pushed to my phone?
There's not an easy answer for that. It partly depends on your location and network topology. See bottom of reply.
yeah I would assume so. Im not sure how push works with multiple email accounts. Like if they all push at the same time or different times. If theyre pushing a different times its definitely eating your battery more.
If they're different mail providers this is true.
However, just having an account with no mail coming in will not drain the battery more than not having it.
This is incorrect, because push is not real push on the iPhone; it's a regularly timed long fetch.
However, why not just set up a forwarding address from those seldom used accounts to the main one?
That's actually a good idea if all the mail accounts are from different providers. If you have a GMail account, you can go to the settings on its web page and set it to do regular fetches from other mail accounts... including letting you reply using those accounts.
-- OP, here's the deal:
Fetch creates a connection to the mail server, asks if there is mail, gets any and closes the connection. This repeats as often as you have set the timer.
Push creates a connection to the server, asks if there is mail, then waits for up to X number of minutes for a reply. As soon as there is mail, the server can immediately send that reply, which acts like a push to the user.
The key is what X is. It depends on the shortest amount of time a device in the network keeps your connection alive.
It can be as long as 45 minutes. It can be as short as 5 minutes. If it's longer, it uses less battery than a 15 minute fetch. If it's shorter, it uses more.
What you need to do is run some tests. Set up different fetch and push situations each day for a week, then try to use the phone about the same each day.