Does exchange push email use more or less battery?

[Malatesta]

It is hard to compare.

Basically it works like this: POP3 is terrible for mobile email, not efficient at all. IMAP is much better.

Exchange is very good on battery, but it also depends on your coverage and amount of email you are getting.

Checking IMAP every 30mins is probably better than Push Exchange, but not by a huge margin.