An Android smartphone could be more energy saving, not only because of the quality of the battery and also the other hard peripherals. Sometimes, it could be affected by the way the users use the smartphone. If you want to save more energy, you need to be more saving battery energy. For example, after transferring a file using Bluetooth, you should shut the Bluetooth down. Such a simple action could add the battery life for more hours.
For more practical, there is an application that can help to shut down the unused peripherals, namely Cenesys. This application could manage some important things affecting the use of the battery.