Alfatronix PT40 battery Guard. The PowerTector Battery Guard is a solid state device that will monitor the battery voltage and disconnect the equipment from the battery if the voltage falls below a pre-determined level.The battery guard ensures that there is always sufficient voltage remaining in the battery to start a vehicle engine or ensuring power is available for other critical applications. The total discharge of a lead acid battery can cause damage to the internal cells significantly reducing the life of a battery, so the battery guard can also be set to disconnect equipment at a lower voltage that will protect the battery from total discharge, while allowing the maximum battery usage. The units are pre-programmed for a selection of scenarios offering higher and lower disconnect voltages allowing users to select a programme to suit their needs from battery protect or shielding key equipment. Other features include, the terminals being insulated using a solid polycarbonate top assembly preventing accidental short circuit, multifunction LED provides programming and status information as well as options for additional visual or audible problem indicators. Ideal for protecting communications gear and ensuring enough charge for starting a vehicle engine.