Airplay/Mirroring and Battery Consumption

Hi, I’ve been using for some time and app called “AirBeamTV (Mirror for Samsung TV)” to wirelessly mirror my rMBP 2015 to my Samsung Smart TV via wifi. I noted that the battery drains pretty quickly. I use it to mirror the rMBP while streaming videos. The battery can easily drop around 20% in an hour usage. I don’t like being charging the macbook so frequently and I am scared that the heavy battery usage can affect the battery capacity and lifetime. In just wonder if this is a common feature of wirless mirroring or it is something specific of the app I am using. How is the battery consumption of mirroring using Apple TV compared with what I am getting with the mentioned app? I’ve been thinking in getting an Apple TV 4th Gen, but just want to make sure I will get something better than what I have now... Any comment is much appreciated. Regards, Tomas