I thought I would post this article about just what the difference is between an Invocation of the God or Goddess and a Charge of the God or Goddess, becasue particuarly to someone who might be new to the Craft and just learning, in apperence they can look very much alike, and it might be hard to draw a distintion between them. But there is a difference in the intent and use between the two.
An Invocation is a way of calling down, or summoning the gods, to bring them into your circile when preforming a ritual and to put an appeal to them, asking them for thier help and calling upon thier power to work towrd your aim and goal in the ritual. It is a way of having the Diety acutally present there with you.
A Charge on the other hand is more of a way to draw upon the power of the God or Goddess and to take it into yourself, to try and gain the wisdom and guidence of the Gods, to feel thier energy flow through your body, but it is not directly calling them down to you, nor putting a request to them, but rather forming a connection with them, to more or less charge yourself with the atributes of the particular diety you are appealing to.