In a shallow bowl, combine the flour, salt & pepper. Lightly dredge each piece of chicken in the flour mixture and set aside.
Pour 3 tablespoons of oil in a large frying pan set over medium-high heat.
Brown half of your chicken pieces in hot oil, being careful not to over crowd the pan.
Continue until all the pieces are nicely browned on all sides, adding more oil as needed.
Place chicken in a 6 quart or larger Crock-Pot.
In a medium mixing bowl whisk together the thawed lemonade concentrate, brown sugar, ketchup and vinegar and pour over chicken.
Cover and cook on HIGH for 3 to 4 hours.
Remove chicken from slow cooker and place on a plate. Cover with aluminum foil to keep warm.
In a small bowl combine the 2 cold water and cornstarch and mix well.
Stir cornstarch mixture into the cooking liquids in the Crock-Pot until well mixed.
Cover and cook the liquid until the sauce is bubbly and has thickened.
Spoon sauce over chicken to serve.
Notes
While most slow cooker recipes can be cooked on either LOW or HIGH heat with an adjustment of cooking time. That is not recommended for this recipe. Longer cooking times with chicken often dry out the meat. A shorter cooking time at a higher heat with a recipe that has some sauce is it is a reliable way to prepare chicken in the slowcooker.