Most on-camera lights are powered by the camcorder batteries. And as you know, camcorder batteries don't last long enough anyway. You can get external lights that mount on your camera's shoe or an accessory bracket. These can be powered by their own built-in batteries or by a battery pack that hangs off your belt. A word of caution.
Lights get hot.
Lights get very hot. Never let kids play with camcorder lights. Lights take a while to cool off and a curious child may come up and try to touch the light, even after it is off. When shooting outdoors or in big rooms, you may need bigger and more powerful lights. Or you can use cheap garage and workshop lights on stands.