SMF (Sealed Maintenance Free) batteries also known as the Valve Regulated Lead Acid (VRLA) batteries. These flat plate batteries that do not require topping-up and normally do not emit any fumes or gases on a continuous basis. They are completely sealed and therefore eliminate the risk of acid spillage during transportation. Due to their construction these can be mounted in any orientation and do not require constant maintenance. These are used for high end applications of standby power like UPS, Electric Converter, Railway Communications, Security Systems etc.