Heat a large skillet over medium-high heat. Cook and stir ground turkey in the hot skillet until browned and crumbly, 5 to 7 minutes; drain and discard grease.
Combine ground turkey, stewed tomatoes, celery, kidney beans, pinto beans, white onion, green bell pepper, red bell pepper, water, tomato paste, jalapeno pepper, sugar, and garlic in a slow cooker; season with chili powder, salt, and pepper.