With an inverter installed on a truck, can the engine be idled to maintain a charge on the batteries to offset the drain by heavy powertool use?

Yes, most of our customers will leave their vehicle running while using their inverter. We recommend that only 2500 watt inverters and below be used on your truck or large vehicle. Advise your vehicle's manufacture or mechanic to make sure your alternator will keep up with the amps being used.