The term ground has always confused me. For instance: I have always thought of a battery as a collection of negative charges at the -pole and positive charges at the +pole. But with this picture what does it mean that one pole is grounded. To be grounded is I guess ideally to be connected to the whole universe. So any charge you had on the pole will effectively spread out to the entire earth leaving no charge at the pole. Am I right so far? Well then in this case what happens to the voltage gap across the battery poles? In the first case it was established because you had to take away electrons from the positive pole and bring them up to negative pole fighting the electric field in both cases. But in the case of a grounded pole, you no longer have to fight the negative charges (or positive depending on which pole is grounded). So doesn't grounding alter the voltage difference?