In a large pot or skillet, brown the hamburger and onion in a little oil. Add chopped peppers and cook until they soften. Throw in everything else except the beans. As for the chili powder, there is no exact measure but start with three tablespoons, then keep tasting and adding more. There are different strengths of chili powder so this is definitely by taste.
Simmer for two and a half hours or so, adding the beans at the last half hour. Stir once in a while.
Serve over elbow macaroni and garnish as you like, or with what is left in the fridge: Sour cream, grated cheese, green onions. Yum!