May be I?m lucky, but since day one I?ve always had good battery life (whether using the standard or extended battery). I?m not rooted and have always used the latest stock ROM and left LTE enabled (I?ve never noticed any discernable difference in battery whether LTE was on or off in a 3G area). The screen is set to auto brightness with a timeout of 30 seconds, no live wallpaper and just a few active widgets (weather/clock app on the home screen and a couple on other screens). Syncing is minimized to just one Gmail account and the weather app default of every 3 hours (all other app syncing is turned off or on demand). Also, I don?t use any type of battery saver app and keep stand alone GPS and Wi-Fi turned off (never use Wi-Fi anyway, but turn on GPS only as needed, then turn off again). All-in-all, the only time I really experience higher battery drain is when USING the phone a lot, which is to be expected.
Also, contrary to what many others have reported, I'm actually getting slightly better battery life now that LTE has been turned on where I live. I'm thinking because the LTE signal around here is stronger than it was on 3G, so the phone doesn't waste battery trying to hold the signal/connection. Since LTE was turned on this past Thursday morning the phone has NOT dropped a data connection once! I experienced the same back in June when spending a week in Denver, again in strong, full LTE areas. As such, I?m convinced that LTE itself doesn?t cause higher battery drain. It's more about the signal and how much the phone may struggle to hold it and/or switch between LTE/3G/1x.