I have left it on overnight at less than 50% and awakened to a phone with between 40% and 45%.
I used to be lucky to finish a round of golf using a gps golf app. This phone uses 15% battery for 18 holes.
Got one for my wife and one grandson who's brother has the latest iPhone, and his brother now wants one.
I could have replied to any number of posts but I’ll respond to yours.
Battery technology, lithium ion included has not created a rechargeable battery with a life span that extends much beyond 500 cycles with a max of about 1000 cycles.
Logically as you would expect... where a “NEW” iPhone 5 or LG or Samsung or _________ gave (gives) maximum battery life initially that power will fall off by percentage points each month of use until the battery is no longer considered useable.
So... a 2 or 3 year old iPhone (or any other battery powered device) will no longer provide 12/14/18 hours between charges (based on talk time) and will “at some point” need to be charged more often in an increasingly shortened window.
So to the guy with an iPhone 4 complaining about battery life... pay to have the battery replaced or buy a new phone.
And to you with the new LG G2... please brag about battery life a year from now at which point your post will have some intrinsic value.