GoKawiilResearchers trace worldwide 60-second power grid pulses to UPS battery tests
A team led by physicist Dirk Witthaut at the University of Cologne analyzed high-resolution electricity data from buildings at Germany's Forschungszentrum Julich campus and found a recurring 60-second demand pulse only in buildings equipped with uninterruptible power supplies (UPS). The researchers traced the fluctuation to tiny battery current bursts occurring exactly once per minute, and the equipment manufacturer confirmed these were automated battery self-tests run by the UPS management software. Because many such devices synchronize their internal clocks to common external time signals, the self-tests end up firing in unison across buildings and even countries.