John W. Wirtz, the man who took his father’s small family engineering business and turned it into an international battery machine manufacturing firm, died on December 3. He was 91 years old.

He was a well known, well liked and entrepreneurial businessman with a fine grasp of technical detail — including numerous patents to his name — and known for his personal generosity to those pushing out the boundaries of battery technology.

He started at Wirtz Manufacturing part-time during his vacations while at high school in the early 1940s. He worked as a machinist and as a result learnt and understood from the ground up what the machines did and why — this tradition of an early start at the ground floor of the business has continued for his son and later through his son to his grandchildren.

He was eventually to become president and owner of Wirtz Manufacturing.

After graduating from high school in 1943, he served in the US Navy until 1946 before attending the University of Michigan, where he graduated in business studies in 1949.

The combination of technical and engineering understanding and a knowledge of business proved a powerful one and through the 1950s and 1960s he criss-crossed North America as an ambassador for the firm.

He was respected by the industry — he served on the board of directors of Battery Council International — and also by his competitors. “John was a well respected member of our industry,” says Mike Tole, chairman of MAC Engineering. “And a true gentleman.”

Another industry veteran recalls meeting him when he was new to the business. “He was courteous, kind and very helpful to myself as a much junior person.”

Colleagues and friends recalled a thoughtful and considerate person. “It has been a pleasure and a privilege to have known him and to have worked for him. For all of his success … both personally and professionally … I have not met a more humble person,” said Ken Benardino a former employee.

The close relationship between father and son — John O’ Wirtz and now head of the the family business — continued well past his retirement. “For over 40 years we spoke about everything,” says his son. “The nice part was that even up until a month ago, he’d stop in and see what we were doing.”

John met his future bride Wanda Ogden in 1940 when both were 15 years of age. They later recalled that they immediately knew that they would be together for the rest of their lives. They were married in January 1950.

His son says: “They were married for 67 years and their relationship was the basis and foundation for everything he would do in his life. If you saw them just three weeks ago before his death you’d have seen them walking together and holding hands like they were teenagers.”

Wirtz was an active Christian being a member of the Grace Episcopal Church where for many years he served in the vestry. He was also a board member of countless local charitable and business groups.

John William Wirtz is survived by his wife Wanda, his two children John and Wendy; his grandchildren, John W Wirtz 2, Jason Wirtz, Robert Wirtz, Justin Wirtz, Alexis Wirtz, Molly Anderson, Robert Smith; and his great grandchildren John O Wirtz 2, Jacob Wirtz, Jason Anderson, Dylan Anderson.

He was preceded in death by brother Walter and sister Dorothy.