Becareful jumping a bike from a car you can damage the bikes electrical system. Some car batteries have too high CCA for our bikes. Putting it through a dead bike battery may offer some protection as I am sure that robs some of the juice. Not good to do though if I want to crank it off my big battery charger I am supposed to set it on the 6V system for cranking to prevent damage. Thats what it says right in the manual for the charger. It is a big floor charger for my towing business and can crank a car over with a dead battery.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!