Place beans in a large bowl and cover with several inches of water. Let soak overnight or at least 8 hours.

Rinse beans and put into an Instant Pot or Crock Pot. Add 7 cups of water (the water should just barely cover the beans), salt, cumin and a whole, peeled onion. 

If using an Instant Pot, set to high pressure for 45 minutes. Let it release naturally. 

To cook them in a crock pot, let cook for 3-4 hours on high. 

Once beans are cooked, remove onion and discard. Either serve the beans with a slotted spoon and serve whole, or leave the liquid in the pot and mash with a potato masher or immersion blender for refried beans consistency. I don't have either, so I used my electric beater.  As they cool they will get thicker. 

These beans freeze very well in individual glass or plastic containers, and can be thawed on the counter, under hot water, or in the microwave for future recipes.  I always like to make this big batch and freeze some for a quick meal in the future.