Heat a large skillet over medium-high heat. Cook and stir beef and sausage in the hot skillet until some of the fat renders, 2 to 3 minutes. Add onion and garlic; cook and stir until meat is browned and crumbly, 5 to 7 minutes more. Transfer beef mixture to a slow cooker.

Stir kidney beans, chili beans, diced tomatoes, crushed tomatoes, celery, bell peppers, chipotle chiles, bacon bits, chili sauce, hot pepper sauce, chili powder, brown sugar, cumin, and salt into beef mixture.

Cook until vegetables are tender and celery retains a slight bite, 6 to 8 hours on Low or 3 to 4 hours on High.