Super Capacitor Jump Starter

In my experience, it was a brief attempt at cranking the engine that lead to the recovery. So it would not seem to depend very much on the specific load applied to the battery. If an excessive amount of energy would be drawn, then when it would heat up there will not be enough. So while it works sometimes it seem that there must be some luck involved. The energy taken to provide the heating must leave enough to provide an adequate amount of cranking to start. And neither the total amount of energy initially present nor the exact amount required to raise the temperature just enough are usually known amounts.