Istanbul is not a stranger to water and power outages. Most of the time when stuff like this happens its due to some maintenance going on. Now, Istanbul is going to have blackouts in the European and Anatolian sides. 
Two companies are in charge of Istanbul's power supply, AYEDAŞ in the Anatolian side, and BEDAŞ in the European side. The power outage plans are published on the supplier websites so you can plan your day accordingly. The information for power cuts for April 2023 can be found on these websites.
BEDAŞ Website
AYEDAŞ Website
It is important to keep your electronics safe during this time. surge and voltage protectors are essential, but if you see the schedule and plan ahead, its best to turn off and unplug your sensitive electronics yourself.
Two companies are in charge of Istanbul's power supply, AYEDAŞ in the Anatolian side, and BEDAŞ in the European side. The power outage plans are published on the supplier websites so you can plan your day accordingly. The information for power cuts for April 2023 can be found on these websites.
BEDAŞ Website
AYEDAŞ Website
It is important to keep your electronics safe during this time. surge and voltage protectors are essential, but if you see the schedule and plan ahead, its best to turn off and unplug your sensitive electronics yourself.