Please do not take this the wrong way - I just really have to ask the quesiton.... If you have a 120 volt outlet in the bed of your truck, what is the power source? Inverter or generator???

If it is just an inverter off the truck battery, then you will kill the truck battery even faster. If you have a generator, then I want to go out flying with you Unlimited power!!!

Another suggestion is to fully charge both batteries the night before you plan to fly (along with your TX and RX batteries). Then the next day, just put the batteries on the charger for 10-15 minutes to "warm them up".. The NiMH batteries give you better performance if they start out a little warm. That will get you two flights in before you even start to chew up your charging capacity.

Lastly, I'm currently using one of these for my limited charging.. 18Ah battery, air compressor, 12v outlets, 400 watt inverter, LED lights and car jump start. It will also be my air compressor for retracts...