He took classes at The College of Wooster, before transferring to The Ohio State University. He was a member of the Delta Upsilon fraternity. Eye problems forced him to withdraw, and he took a job as foreman of a telephone line crew. At first, the termination of his studies caused him to be depressed. Then he found ways to apply his electrical engineering skills on the job, and his spirits revived. He also met his future wife, Olive Williams. When his eye condition improved, he was able to return to his studies and graduated from OSU in 1904 with an electrical engineering degree.

Kettering married Olive Williams of Ashland, Ohio, on August 1, 1905. Their only child, Eugene Williams Kettering, was born on April 20, 1908. Eugene W. Kettering joined Winton Engine in 1930, which was acquired by General Motors and was eventually incorporated into the General Motors Electro-Motive Division (EMD). The younger Kettering became a central figure in the development of the EMD 567 and the Detroit Diesel 6-71, serving at EMD until his retirement in 1960.

Kettering was hired directly out of school to head the research laboratory at National Cash Register (later known as NCR Corporation). Kettering invented an easy credit approval system, a precursor to today’s credit cards, and the electric cash register in 1906, which made ringing up sales physically much easier for sales clerks. Kettering distinguished himself as a practical inventor. As he said, “I didn’t hang around much with other inventors and the executive fellows. I lived with the sales gang. They had some real notion of what people wanted.” During his five years at NCR, from 1904 to 1909, Kettering secured 23 patents for NCR. He attributed his success to a good amount of luck but added, “I notice the harder I work, the luckier I get.”

Beginning in 1907, his NCR colleague Edward A. Deeds convinced Kettering to develop improvements for the automobile. Deeds and Kettering invited other NCR engineers, including Harold E. Talbott, to join them nights and weekends in their tinkering at Deeds’s barn. They became known as the “Barn Gang,” and Kettering was called Boss Ket. Their first goal was to find a replacement for the magneto. In 1909, Kettering resigned from NCR to work full-time on automotive developments, and the group incorporated as Dayton Engineering Laboratories Company, or Delco.

Kettering held 186 U.S. patents. He invented the all-electric starting, ignition, and lighting system for automobiles. Electric starters replaced crank (manual) starting of automobiles. First incorporated in the 1912 Cadillac, all-electric starting aided in the growth of the US auto industry by making the automobile easy for anyone to start. Other patents included a portable lighting system and an incubator for premature infants. His engine-driven generator was combined with storage batteries to form a “Delco Plant”, providing an electrical power for farmsteads and other locations far from the electrical power grid.

Kettering’s key insight lay in devising an electrical system performing the three functions it still serves in modern cars: starter; producer of spark for ignition; and source of current for lighting. Leland ordered 12,000 self-starters for his 1912 models; Delco had to then transition from its research and development activities to production. The invention won a Dewar Trophy in 1913.

Kettering helped found the Engineers Club of Dayton in 1914.

In 1914, Flxible Sidecar Company was incorporated with the help of Kettering, who then became president of the company and joined the board of directors. Kettering provided significant funding for the company in its early years, particularly after 1916, when Kettering sold his firm, the Dayton Engineering Laboratories Company (Delco), to United Motors for $2.5 million. Kettering continued to serve as president of Flxible until he became chairman of the board in 1940, a position that he held until his death in 1958.

Kettering and Deeds had a lifelong business, professional and personal relationship. In 1914, recognizing that Dayton was among the leading industrial cities in the US because of the skilled engineers and technicians in the city, they founded the Engineers Club of Dayton and the Foreman’s Club of Dayton, which later on became the National Management Association.

Charles Kettering built a house, “Ridgeleigh Terrace”, in 1914. According to local sources, this house was the first in the United States to have electric air conditioning. Ridgeleigh Terrace was the home of his son, Eugene Kettering, until his death. Eugene’s wife, Virginia Kettering, lived in the house for many years, restoring and redecorating it. In the late 1990s, the house was seriously damaged in a fire, but it was rebuilt according to the original blueprints.

Delco was sold to General Motors in 1918, as part of United Motors Company. Delco became the foundation for the General Motors Research Corporation and Delco Electronics. Kettering became vice-president of General Motors Research Corporation in 1920 and held the position for 27 years.

Between 1918 and 1923, he led the research and development at GM’s Dayton research laboratories to commercialize air-cooled engines for cars and trucks. They used fans forcing air across copper fins for heat dissipation. The commercialization, attempted between 1921 and 1923, was unsuccessful due to a combination of factors, nontechnical and technical. Air-cooled engines have had commercial success before and since, in various fields (small engines, aircraft, cars), but the historical moment of GM’s “copper-cooled” automotive engine was inauspicious.

In 1918 Kettering designed the “aerial torpedo”, nicknamed the Kettering Bug. The 300 lb papier-mache missile had 12 foot cardboard wings, and a 40 hp engine. It could carry 300 lbs of high explosives at 50 mph, and cost $400. The “Bug” is considered the first aerial missile, and lessons learned from the “Bug” led to development of the first guided missiles, as well as radio-controlled drones.

Kettering’s research in fuel was based on his belief that oil would be in short supply and additives would allow more efficient engines with higher compression. His “high percentage” solution was to mix ethanol with gasoline, while his “low percentage solution” looked for additives that would be added in small quantities to increase what later would be called the octane rating of gasoline. Thomas Midgley Jr. and Kettering identified tetraethyllead (TEL) in December 1921 as an additive that would eliminate engine knocking at a dilution of one thousand to one. While use of ethanol could not be patented, TEL’s use as an additive could. Kettering and Midgley secured its patent and proceeded to promote the use of TEL as an additive instead of other options. Kettering became the first president of the newly founded Ethyl Corporation that started to produce TEL in 1923. One year later, he hired Robert A. Kehoe as the medical expert to proclaim that leaded gasoline was safe for humans. That its use was an ecological disaster leading to a global lead contamination was not acknowledged until many decades later.

His inventions, especially the electric automobile starter, made him wealthy. In 1945, he helped found what became the Memorial Sloan Kettering Cancer Center, based on the premise that American industrial research techniques could be applied to cancer research.. His son and daughter-in-law, Eugene and Virginia, created Kettering Medical Center in Ohio, as a tribute to Charles Kettering’s life and his work in healthcare research.

The city of Kettering, Ohio, a suburb of Dayton, was named after him when it was incorporated in 1955.

Kettering died on November 25, 1958. After his death, his body lay in honor at the Engineers Club and then was interred in the mausoleum at Woodland Cemetery, Dayton, Ohio.

On January 1, 1998, the former General Motors Institute changed its name to Kettering University to honor Kettering as a founder.

In 1998, GMI Engineering and Management Institute (formerly General Motors Institute), of Flint, Michigan, changed its name to Kettering University in honor of Kettering. His ideals, prowess, and belief in co-operative education continue there. Kettering is also remembered through the Memorial Sloan-Kettering Cancer Center, a cancer research and treatment center in New York City, and through the Kettering Health Network, which includes several hospitals and medical center campuses as well as Kettering College in Kettering, Ohio.