The governing body of a municipality, within thirty days after the provisions of this article become effective as to the municipality, shall call an election for the purpose of selecting departmental members of the board. The election shall be held at the city or town hall or such other convenient place as the governing body may determine, and during such hours as will enable all qualified persons to cast their ballots. Balloting shall be secret and each permanent member of the police department, regularly appointed and qualified, shall be entitled to vote for as many candidates as there are places to be filled. The vote shall be canvassed and the result announced by the governing body within one week after the election. The members of the department, to the number of places to be filled, successively receiving the highest number of votes, shall be declared elected. Thereafter a regular election shall be held annually on the second Monday in January of each year.