Rinse dried pintos under cool water and drain. Put them into a large bowl and cover with hot water and let sit over night.This helps cut down on cooking time and take some of the "gas" out. They will swell quite a bit so you need a large bowl.In the morning, rinse beans well with cool water, drain and then put in crock pot.
Add chicken broth and all other ingredients. Fill with water till water is about an inch or 2 above beans.
Cook on low all day for about 8-9 hours.
Notes
If you like your beans with a little kick, add in some minced jalapenos with the onion. You can remove the seeds for less bite or leave them in for more heat.