The battery life is the same as the phone that comes with your phone. Personally I let the battery in my phone go completely dead and then swap batteries. This makes sure I keep the longest battery life possible. Depending on what you run on your phone, the quality of service in your area, and the actual use of your phone will determine how long a single charge will last you. I get about 8 - 10 hours each day and the quality of service in my area is not great, so I leverage WIFI to avoid the searching for service consumption.