i don't typically use the built in email apps on Android devices because i use the Gmail app. i have all my email accounts fetched or IMAP'ed to Gmail. late last night, i wanted to transfer a couple of files from my phone to the computer so i emailed them to myself using the Gmail app. it was taking too long just sitting in the outbox trying to send it which is typical from time to time with the Gmail app.
i decided to login to my Gmail account with the built in email app and sent my attachments that way. since i don't plan to regularly use this email app, i set sync for both peak and off peak times to manual. i plugged the phone in for the night and went to bed.
i started using the phone earlier today. after only being unplugged for 2 hours with only 18 minutes of screen use, my battery was already down to 3.71v which the phone reads as 50%. this phone with the same battery typically last 14 hours with 2 hours screen use and an hour of phone calls.
i checked the screen that shows a bar graph of what's using the battery and "accounts & sync" is there showing 2% of usage. before today, i have never seen accounts & sync being there. with the email i set up last night, the only other things that are activated under accounts & sync are the required Google account, and the Facebook app that syncs Facebook contacts with the phone.
i removed the email account, fully recharged the phone and the battery life seems back to normal.
i will wait another 5 hours, i will recharge the phone, re-activate the email account, and see if that's what killed my battery today.