upgraded my data from 200mb per month to 3 gigs per month and have a question

So since i've always had the 200 mb data plan, I only turn on my data when i want to use it and don't have wifi available. But now with this 3 gig plan I can just leave it on for the whole month and not worry about it.

now my question is about battery life. will having both the wifi and data turned on drain my battery to death? should i always use wifi when available, or just go with the LTE?