LeftieBiker said:
You can accomplish the same thing by using the biggest AGM battery that will fit in the Leaf's battery holder - or make a slightly larger one. 150AH might give you enough of a charge to go a few miles. Interestingly, there is anecdotal evidence that as the Leaf gets very low on charge, it will pull power from the accessory battery through the DC-DC converter to go a few more meters. IF true that would eliminate the need for the inverter.
Since the inverter is doing DC to DC one way, seems the traction batteries would eat the power if it did switch in reverse instead of going to the motor. Unless it can cut-off the traction battery, up the voltage and then feed into the motor and still run all the 12 volt accessories, computer, etc without the voltage dip messing everything up, then you would have the ability to "creep" @ 500 watts maybe, but not sure how far or how long.