In a simple answer? No. When the LG G3 was announced last month, and we saw all the specs, including the same size battery as we had in the LG G2 last year - despite the larger screen and double the pixels in the LG G3 - many of us thought that battery life would be terrible. Well I was pleasantly surprised to find out that we were wrong. Now it's important to state that I have been using a Korean LG G3 here in the US on T-Mobile, so that we should see even better battery life once we get the US variants of the LG G3 in. But so far, so good.
I've been posting my results of battery life pretty much everyday on Google+. I've gotten 6 hours on screen a few times. I also did a test with using it at 50% brightness all day (something I'll be doing with all devices in the future, because it seems I'm one of the few that uses it at 0% brightness all day, except when I'm outside) and I still got 3.5 hours with around 15 hours off the charger. Still not bad if you ask me. It's not quite up to the LG G2's battery life, but it's right there with the Samsung Galaxy S5 and the HTC One M8, which I wish I had one or both here to compare it with to see exactly how close it is.
So far I'm happy with battery life. And that comes from a guy who's first question is how's the battery life? Now I have been on WiFi, since I'm always roaming with the LG G3, so it's worth noting that. But even when I've been away from home, and on HSPA+, it's done pretty well. Like I said, not quite LG G2 level battery life, but it is on par with the other 2014 flagships. It'll definitely get you through a full day and then some, especially with the amazing standby battery it's got.