Donát Bánki worked for Ganz Factories firstly as a constructor, and as a chief engineer in his last 8 years.

For years he worked with János Csonka and they released many patents together. The most famous of these was the Bánki-Csonka engine, which brought international fame for the inventors. In 1893, they had the carburettor patented 6 months before Maybach did the same.

In 1894 he had his high-pressure combustion engine patented, the Bánki-engine, in which vaporized water cooled down the mix of fuel and air, making the engine more efficient. His first FWD car was completed in 1902, which solved several problems faced by rear-wheel-drive cars. The automobile was made in the Ganz factory, and it had its engine, gearbox and differential placed in the front of the automobile.

In 1917, he invented the Bánki-turbine, which created opportunities for smaller hydroelectric power plants. He created a plan to harvest the hydro energy at Iron Gates.

He became a correspondent of the Hungarian Academy of Sciences in 1911.