Percival Waddams Petter was born on 26 May 1873 to James Bazely Petter an ironfounder in Yeovil, Somerset, and Charlotte Waddams (née Branscombe). Both parents had been raised in the Exclusive Brethren, but broke with them in 1883, after which they attended the local Anglican church. 'Percy' Petter maintained an ambiguous commitment to Brethrenism despite an allegiance to the Church of England.
Educated at Yeovil Grammar School, he married Emily Jane Kennan in 1904, and they had two sons and four daughters. Along with his brother he produced an early internal combustion engine car in 1895, but it was not a commercial success. In partnership with his brother he set up Petters Ltd in 1901 producing stationary and marine oil engines. During the First World War they set up Westland Ltd to produce military aircraft, which they continued to do after the war. The businesses were eventually sold in 1936, when both brothers went into retirement. Percy was Mayor of Yeovil in 1926-7. His wife Emily died in 1935, and he was married to Ruth Penson-Harris in 1946. Percy was an active preacher and publisher of tracts for much of his life. He died on 15 September 1955 aged 82.