Spray 3 to 5 quart crock pot with non-stick cooking spray.
Rinse beans and drain.
Separate onion slices into rings.
Put all ingredients into crock pot, stir to combine.
Cook on high 4 hours or low 8 - 10 hours.
Hints: *Use whatever combination of beans you have on hand, but don't use seasoned beans. *It's MUCH better made with wine; the alcohol cooks off; you can buy tiny bottles in a four pack if you're not a wine drinker. *Leave the thyme sprigs whole; the leaves will fall off during cooking. Remember to fish out the stems before serving.