I just got my Lg G4 a couple of weeks ago. Switched over from iPhone 6. I have to say I like a lot of things about the G4, but the battery is awful!!
I get about 2 to 3 hours of battery when using it very little. By very little I mean check email 4 or 5 times, send 2 or 3 files to Evernote, check the weather 2 times and make 1 phone call and answer 1 phone call and do 3 or 4 text messages.... that's it!! It is pretty much useless as a mobile device. I literally have to do a full charge it 3 times a day minimum. I have deleted all but stock apps. I have turned off all running apps. I even went so far as to do a factory restore but it didn't help at all. I even tried using the gps and I had it on for 45 minutes and the battery died. If I have it plugged into a car charger while using the gps it discharges faster than it charges. However, with it plugged in I can go for 2 hours with the gps before it reaches 5% battery. All I can say is it's good that I can swap out the battery. I need to carry a dozen fresh ones with me for a days work.
Compare this to my iPhone 6 that gets used almost constantly all day ... countless phone calls, text messages, playing games, reading ebook, checking weather, doing calculations on calculator app, do web searches, a few internet downloads ... the screen is on a lot and by the end of the day i'm still at 48% battery.
Do I regret switching from iPhone 6 to Lg G4? You bet I do. This G4 is going into the drawer and I'm using the iPhone again. Waste of money.