Trying to Figure Out Configuration with Battery Pack for Costume

Hello! I hope I am posting in the right section. I am trying to work out how to configure two intense high lumens lights to a battery pack. These lights would be the intensity of a spotlight, if not a spotlight. My questions are: how would I attach the two lights to the battery pack? Do I solder them? If the lights I purchase have a plug cord, do I open the cord and solder the wires? What kind of battery pack can handle super intense lights? And how would it work to switch between the two lights, one on, one off, or both off? I purchased some LED tape with battery packs which are set up to be soldered together for a different project and I have leftovers which I was hoping to use but I assume these battery packs might not be strong enough to handle a really bright light, and as I said, I need to configure it so the switch on the battery pack can turn one on and the other off, and also both off. Any advice is appreciated!