Stab potatoes with fork.
Wrap each in foil.
Fill crock pot with potatoes.
Cover and cook on High 2 1/2- 4 hours.
Do not add water.
Cooking time depends on how big your potatoes are.
Use your best judgement.
It doesn't hurt to cook them for the 4 hours.
For large potatoes, I have cooked five to six on Low for 8 to 10 hours and they turn out perfectly.