On Wednesday, April 10, 2019 at 1:52:47 PM UTC-4, Rod Speed wrote:

But in some situations the problem is that the car that wont
start will turn the engine over fine but the voltage sags enough
so that the ignition cant supply a good enough spark to get
the engine to fire and all the car that is helping to start it
needs to do is supply enough voltage to get the engine
to actually fire and that doesnt require much current.

I'm throwing the bull**** flag on this. It has always taken more power to turn an engine over mechanically than to get a spark plug to fire.