Slow Cooker BBQ Ribs

1 red onion, medium sized, chopped
3 garlic clove, peeled and minced
1 lemon, juiced
1 cup brown sugar, packed
1/2 cup cider vinegar
1 cup ketchup
2 tablespoon Worcestershire sauce
1/2 teaspoon
3 racks of baby rack ribs, cut into 3-4 rib pieces

Heat onions and garlic in a skillet on medium heat in vegetable oil until softened and slightly brown. Stir in remaining ingredients except ribs and simmer gently for about 5 minutes. Remove half the sauce and save for serving. Add ribs and sauce to slow cooker and cook on low for 7-9 hours or on high for 4-6 hours.