Place the ground beef in the bottom of the slow cooker. Break it into a few large pieces with a spoon.
Add the crushed tomatoes, kidney beans, and black beans on top of the beef.
Sprinkle the chili powder, cumin, garlic powder, onion powder, salt, and black pepper over the ingredients.
Stir everything together, breaking the beef into smaller pieces as you mix.
Cover and cook on low for 6 to 8 hours.
Stir the chili well before serving to distribute the meat evenly.
Ladle into bowls and add shredded cheddar cheese and sour cream to taste.