In a large dutch oven add the bacon on medium heat.
Cook until fat has rendered and bacon is crispy but still chewy, about 1 minute.
Remove bacon.
Add in onions and cook until translucent, about 5-6 minutes, stirring occasionally.
Add in navy, pinto and northern beans and stir.
Add in tomato sauce, water, dark brown sugar, yellow mustard, chili powder, salt and pepper and stir.
Bring to a boil then reduce to a simmer.
Cook for 45-60 minutes until thickened.