For sauce, in a small saucepan combine cranberry sauce, maple syrup, catsup, vinegar, and onion powder. Bring to boiling. Reduce heat; simmer, uncovered, for 5 minutes, stirring occasionally. Rinse chicken; pat dry with paper towels.
In a covered grill, arrange medium-hot coals around a drip pan. Test for medium heat above the pan. Place chicken, bone side down, on grill rack over drip pan. Cover and grill 50 to 60 minutes or until chicken is tender and no longer pink, brushing occasionally with sauce during the last 10 minutes of grilling.
Preheat gas grill. Adjust heat for indirect cooking. Test for medium heat where chicken will cook. Place chicken on grill rack over medium heat. Cover and grill as directed.
To serve, cut each chicken half into two or three pieces. Heat remaining sauce until bubbly; serve with chicken. Makes 4 to 6 servings.