Thanks phk abd Jim, I guess the best thing to do is just use the truck battery at the field and get myself a couple of sets of batteries and rotate through charging and flying them. That 12V DC power is a good one, but man there goes another $70. Not to mention the Electrifly 3600's are $50 per pack and I need two for a flight. So, if I only get one extra set plus the charger I am looking at $170 more even bothing to head to the field. Well, like they say, "The only difference between men and boys is the price of thier toys".