In 1908, a Cadillac owner named Byron Carter stopped to help a stranded motorist on the Belle Isle Bridge in Detroit. The car backfired while he cranked it. The handle whipped around and shattered his jaw. He died of complications weeks later. His friend Henry Leland, who ran Cadillac, went back to his engineers and said: find me a way to start a car without a crank, or I close the company.

The man who solved it was Charles F. Kettering, a former patent examiner who had left NCR to found Delco (Dayton Engineering Laboratories Company) in a barn in Ohio. He filed his solution as US Patent 1,150,523, "Engine Starting Device," in 1911, issued August 17, 1915. Cadillac shipped it in the 1912 model year. Within a decade, the hand crank was dead.

The straightforward reading of Kettering's patent is: he built a small electric motor that spins the engine's flywheel until combustion takes over. But the real invention — the thing that made it commercially possible — was a subtler trick.

A starter motor big enough to crank a cold engine draws hundreds of amps. Making it that powerful means it's absurdly overbuilt for the two seconds a day it's actually used. Kettering's insight: run the same machine backwards as a generator while the engine is running. The starter charges the very battery that just fired it. One motor, two jobs. Suddenly the "wasted" copper and iron pay for themselves every mile.

This dual-role machine — motor when you need torque, generator when you don't — is the exact architecture of the modern electric powertrain.

• Mild hybrids. Every 48V "integrated starter-generator" (ISG) shipping in Mercedes, Audi, RAM, and Ford trucks today is Kettering's 1915 patent scaled up. Same machine motors the crankshaft at startup, harvests energy at braking, and boosts torque at acceleration.
• Full EVs. Regenerative braking in a Tesla, Rivian, or Lucid is the Kettering trick applied continuously — the traction motor becomes a generator every time you lift the throttle. The bidirectional inverter that makes this possible is a direct descendant of the mechanical commutator Delco used to switch the machine's role.
• Peak vs. continuous overdesign. Kettering also established the pattern of sizing a machine for a brief, punishing peak (cranking, 0-60), not steady-state load. Modern EV motor controllers do the same thing: they briefly pull 3-5× continuous current for launch, then throttle back before the windings overheat. The thermal math is more elaborate now, but the philosophy is Delco's.

There is a second modern echo worth noting. The self-starter forced automakers to standardize a reliable onboard electrical system — battery, charging circuit, wiring harness, voltage regulation. Radios, headlights, wipers, ignition coils, fuel injection, and eventually engine computers all rode on infrastructure that only existed because Kettering needed 200 amps to spin a flywheel. The modern "software-defined vehicle" begins, weirdly, with a dead man on a Detroit bridge.

Kettering went on to run research at General Motors for 27 years, filed 186 US patents, and co-founded what became the Sloan Kettering Cancer Center. But his most consequential invention was the one nobody notices: the moment you press a button and the car just goes.