I have to videotape in the field for a baseball team, and I need an external battery that provides AC output that I can switch between my camcorder's power cord and my laptop's power cord. I only see using it about 2 hours max a day and then charging overnight. I don't want a external laptop battery because there would be no AC outlet for the camera that has the weaker battery. I looked into extra batteries for the two but that got expensive real quick. Thanks in advance