This is my favorite way to prepare black eyed peas. For a little smokiness I add a smoked pork shank. And for a little spiciness I add a little jalapeno.
Cover and cook on low for 8 hours. Note: If you wish to add smoked ham, do so 6 hours into cooking.
Remove ham hock and let cool slightly.
Cut meat from the bone, chop, and return to the slow cooker.
Remove the bay leaf before serving.
Notes
You don't want to overcook the peas. Since slow cooker temperatures can vary, check them after 6 hours and every 30 minutes after to test for doneness.