After using mine for a few months now, I am sad to say, I am very dissapointed in the standard batteries. We have phones that do EVERYTHING but we can not use a fraction of EVERYTHING. With the ZeroLemon, this is possible. I have read that people very frequently get up to 3 days of use. I am very happy if i have to charge it once a night after about 16 hours of very heavy use. I am one that utilizes everything a phone has to offer and am always trying to take it even further. The hardest habit to break is always eyeing the battery. After a decade of always having to find an electrical outlet or always plugging it into the car adapter, I no longer have to worry, ever! My 2 biggest gripes about this battery is the Galaxy S4 battery percentages. It DEFINITELY is not very accurate based on what we are used to with the standard batteries, and the fact that once you hit 5%,the camera will not work. Once my S4 hits 2%,i usually have about 3 hours of use. 1%, about an hour. It would be nice to be able to take pictures up until it is about to die. Both of these gripes could be solved with a simple app.
The bulk of it is the same as an OtterBoxed HTC Vivid. I have gotten so used to the feel, that i cant use the phone without the battery. I have tried to use the stock battery twice now. I was using my phone like normal and 3 hours later it was dead. That is a slight comparison to the stock battery vs. ZeroLemon. With me being sloppy and not watching battery life, I have seen 1 Day, 16 Hours on my usage with the screen on 51% of the time. Pandora, GoogleMusic, etc. is almost always running in the background.
The best investment I have ever made for the return I got from the money I spent.