If the 4G(LTE) signal is OK then there is not much difference compare to 3G. The problem is of 4G signal is weak, then the phone is looking for the signal non-stop and this drains battery very much.
This depends on the handset, Size of battery and the optimization features however yes it will but it depends on what you are doing ie: Watching streamed video content and if you loose 4G then your phone will be searching using your battery quicker
If the 4G(LTE) signal is OK then there is not much difference compare to 3G. The problem is of 4G signal is weak, then the phone is looking for the signal non-stop and this drains battery very much.
