A late reply as I think my lambo is the updated L Rider in Chrome (SS according to the leaflet) and I've only just read this..
Mine can't draw more than 2.5 amps, will drop the volts without telling you if you go over, so I worked out the volts and atty resistances based on that. According to my quick calcs you can't hit 6 volt with any atty below 2.5 ohms, no matter how good your battery. With a 1.4 ohm atty your volts won't be nuch more than an ego, but you should get the full amps from it.