Spray 3 1/2- to 4-quart slow cooker with cooking spray; set aside. Pour chili beans into medium bowl. With potato masher or fork, mash about half of the beans; set aside.
In 12-inch skillet, cook beef, green and red bell peppers, onion and jalapeño chile over medium heat 8 to 10 minutes, stirring occasionally, until beef is brown; drain.
Pour beef mixture into slow cooker. Add beans, ketchup, chili powder and pepper. Stir to thoroughly combine. Cover; cook on Low heat setting 2 1/2 to 3 hours or until heated through (165°F). Stir in lime juice.
Divide beef mixture among buns (about 1/2 cup each). Serve immediately.