Place a large skillet over medium heat. Arrange 6 slices bacon in a single layer and cook until crispy, flipping as needed, about 12-15 minutes. Transfer to a paper towel-lined plate to drain. Once cooled, chop into small pieces.
Add the crumbled bacon, 31 ounces canned red kidney beans, 15.5 ounces canned great northern beans, 15.5 ounces canned pinto beans, 1/2 large white onion, 4 cloves garlic, 1 cup honey barbecue sauce, 3/4 cup ketchup, 1/4 cup dark brown sugar, and 2 tablespoons Worcestershire sauce to a slow cooker and stir to combine.
Cover and cook on LOW for 6 hours. Stir halfway through the cook time if possible.
Serve immediately or turn the slow cooker to WARM until ready to serve.
Notes
For vegetarian baked beans, omit the bacon and add a small splash of liquid smoke if desired.
For smokier beans, use hickory BBQ sauce or add liquid smoke to taste.
For thicker beans, cook uncovered on HIGH for the last 20 to 30 minutes, stirring occasionally.
For a heartier version, stir in cooked ground beef, sausage, or pulled pork.
Keep on WARM for serving at parties or potlucks, stirring occasionally.