Cook 8 slices of bacon until cooked but not crisp. Drain well on paper towels.
Season each chicken breast with salt and pepper. Then wrap each chicken breast with 2 strips of bacon and place in crock pot. Top with onion, crushed pineapple, and bbq sauce.
Cover and cook on low for 4 to 5 hours or until chicken is tender. Cook remaining bacon until crisp. Drain and crumble the bacon and sprinkle over each serving.