Rinse the beans, drain, and place in your slow cooker.
To the slow cooker, add the onion, garlic, chili powder, and sausage if using that.
Add the water and broth, stir to mix, cover, and set the slow cooker to High setting and cook for at least 5 hours, without lifting the cover.
At the 5 hour mark, check the beans for tenderness. If the beans are not tender, continue cooking, checking again each hour until tender. (Mine were done, and perfect right at the 5 hour mark.)
When the beans are tender, stir in the tomatoes and lemon juice. Turn the slow cooker to Low setting and cook for another 30 minutes.
You can leave on Keep Warm for several more hours if needed, and this blends the flavors as well.
Just before serving, open and stir in the pork broth powder.
Serve with bread, biscuits, or even over rice. Enjoy.