No special township meeting shall be convened unless 15 or more electors are present at the meeting. The electors at special township meetings when convened have the powers enumerated in this Article. An elector is a person registered to vote within the township no less than 28 days before the date of the special meeting. If a special township meeting is not convened because of an absence of 15 or more electors, that special township meeting shall not be re-convened unless all procedures for a special township meeting are again completed.