Soak beans overnight (or for a shorter period if beans are fresh). Drain.
Combine soaked beans and water in crock pot; stir. Cook on high for a couple of hours, or until they start to soften.
Add remaining ingredients and cook an additional 3-6 hours or until cooked to desired doneness.
Drain any excess liquid and remove onion halves. Mash beans, adding reserved liquid to desired consistency.