@Fourdoor you may not like this idea, but you could consider a YouTube Premium subscription. If you go premium, you can keep a video playing with the screen off, which will help with your power consumption. You can also pre-download videos at home/work/wherever over WiFi and play them back in your car without using mobile data or keeping the phone's radio busy (further reducing your power draw). In addition to those great things, you also get no pre-roll or interrupting-my-video-every-few-mins ads, access to YouTube Music premium, and probably some other perks. Something to consider, anyway.