Valve Regulated Sealed Cell (Battery) : A battery in which the cells are closed but have a valve which allows the escape of gas if the internal pressure exceeds a predetermined value (pressure)
Young & Company Electric Power Products and Related Engineering Services, Glossary of Electrical Terms, http://www.youngco.com/young2.asp?ID=4&Type=3, CA., USA 2001. (Electr Sfty - Amer) {514}