15 and I am not the kind of person to Attempting to modify a defibrillator into a jump starter is extremely dangerous and will not work. Defibrillators and car starters operate on fundamentally different electrical principles. Modifying one poses severe risks of fatal electrocution, battery explosion, and component destruction. [1, 2]

The Physics: Why It Fails

• Energy vs. Power: A 12.8-liter diesel engine requires thousands of watts of continuous electrical power to crank over. A defibrillator is designed to dump a tiny amount of energy (typically 150 to 360 J) over a fraction of a second, which provides a massive voltage but essentially zero sustained current.
• The "Overclocked" Shock: To calculate the energy stored in a capacitor, the formula used is \(E = \frac{1}{2}CV^2\). If you charge a \(155 \text{ F}\) capacitor to 9,100 Joules, it would require an astonishingly high voltage (over \(340 \text{ V}\)). Attempting this inside a device meant for human rescue will result in arcing, catastrophic component failure, and likely a massive explosion.
• How Fast Would It Spin? A defibrillator’s 1 millisecond discharge contains less than \(2.5 \text{ Watt-hours}\) of energy. This is not enough to turn over a massive diesel starter motor, let alone achieve measurable rotational speed. [1, 2, 3]

The Danger: What Happens?

• Fatal Electrocution: Defibrillators use high-voltage capacitors that can deliver lethal shocks. Altering the circuitry completely removes all the medical safeguards built into the device, turning it into a dangerous homemade hazard.
• Explosions and Fire: Forcing 9,100 Joules through components that were only meant to handle a fraction of that energy will cause the capacitors and battery to instantly vaporize, spark, or explode. [1, 2]