The ekey uninterruptible power supply for series installation with 230 VAC input voltage, 12 VDC output voltage and 4 Ah capacity ensures the power supply of the ekey devices in the event of a power failure. This uninterruptible power supply is intended for use in the home and business sector. The ekey uninterruptible power supply for series installation is intended for fixed installation on a DIN rail in, for example, a distribution box (8 HP + 9 HP) and for use in protected indoor areas.