pi@Pi-Hole:/var/log $ sudo zgrep -i -c voltage /var/log/syslog*
/var/log/syslog:0
/var/log/syslog.1:0
/var/log/syslog.2.gz:0
/var/log/syslog.3.gz:0
/var/log/syslog.4.gz:0
/var/log/syslog.5.gz:0
/var/log/syslog.6.gz:0
/var/log/syslog.7.gz:0
pi@Pi-Hole:/ $ sudo dmesg -T | grep -i voltage
Returns nothing