Buffer power supplies

Buffer power supplies (also known as DC UPS and back-up power supplies), are units that allow a battery to be attached to the power supply so that the energy contained in the battery maintains the power supply at the output for a period of time in the event of a mains failure. They are used to provide power continuity for equipment, industrial, IT, building automation. They contain a charger that keeps the battery charged and when the mains supply fails, they maintain the supply by drawing energy from the battery connected to the output. A feature of buffer power supplies is that their output voltage is equal to the battery voltage, i.e. usually 13.8V. They are available in versions with the battery integrated inside the enclosure and those where it is connected by cables from the outside. They have indication of battery status, presence of mains voltage, etc.