[CentOS] Power Cut

Dear All I am using a centos server for cdr billing and mediation device on a remote network. I am experiencing problem that I am suspicious it comes from main supply power cut at the remote site. The power supply to the remote site comes from battery charger that will be automatically switched in circuit under main supply power cut but cannot provide adequate power for more than 2 hours . I am suspicious that the remote system is suffering from many frequent main supply power cut . Can you please do me favor and let me know if there is any log on my centos server that I can check to see if there would be many frequent power cut there ? Thank you for your time