They aren't power hungry.
Stock they do just fine with a maintenance free or well maintained battery and even have a little extra to spare.
If you are talking speed power, they do fine hangin with the bigger bikes.
Even the tricked out Goldwing has to move up to a bigger alternator to handle extra doo-dads after a point.
Patriot Guard Rider
2000 VN750 Sere (Serendipity)
1990 GL1500 (Ole Blue)
1986 VN750 EVie (project bike, heavy custom)
VROC # 11628 / 25000-H
ARVROC # 12 Coordinator and Crowd Control
OKVROC # 18 (H)
TNVROC # 45 (H)