In a large skillet over medium-high heat, brown the ground beef with the diced onion until the meat is fully cooked and the onion is softened, about 8-10 minutes. Drain excess fat.
Transfer the cooked beef and onion to your slow cooker.
Add the kidney beans, crushed tomatoes, tomato sauce, chili powder, cumin, garlic powder, salt, and pepper. Stir everything together until well combined.
Cover and cook on low for 6 hours or high for 3 hours, stirring occasionally if possible.
About 30 minutes before serving, stir in half of the crumbled bacon and 1 cup of shredded cheddar cheese.
Serve hot, topped with remaining bacon, cheese, and your favorite burger toppings like sour cream, pickles, and diced tomatoes.