Motorola RAZR V3xx

I have gone through two Razr V3xx and I think three batteries. The problem is that when the AC adapter is not plugged into the phone the meter always reads full. When I plug in the AC adapter the battery meter reads the true (not full) battery life (4 or 2, for example in phone status or less than 3 on the main screen). When I disconnect it from the phone the battery reads full.

How can I correct this so that the phone does not always read full when it is not charging?

Thanks.