Wash beans and place in a large kettle. Cover with water 2 inches above bean line and let soak overnight. Drain in morning.
In 2 quarts of water, add soaked beans & ham hocks and bring to a boil. Add onion, tomatoes, chili powder, lemon juice, and pepper to taste.
Simmer 3 hours OR if using a crock pot - 3 hours on high & 5 hours on low.
Remove ham hocks before serving. Makes 4 quarts.