Lines crews from Northpower mobilised to repair a fault south of Ruakaka where 672 customers are currently without power about 9pm yesterday.
The outage follows a large tree taking down lines.
Northpower Network General Manager Graham Dawson said power should be restored to most of the affected customers this evening.
Provided there are no further outages caused by the remnants of Cyclone Lusi - only 100 Northpower customers around Whangarei District will be without power overnight.
Lines crews will complete remaining repairs from shortly after 6am, Sunday morning.
Mr Dawson said while Cyclone Lusi still poses a threat to Northpower's electricity lines network in Kaipara and Whangarei, he wants to thank locals for their patience and co-operation over the past 24 hours.
"The way our community has worked with our staff to alert us to outages has helped minimise outage times," Mr Dawson said.
"I have been in the field today with our lines crews and arborists. They've been exposed to fairly challenging conditions and they've done the job. So far, the Northpower Network has held up well.
"We may still face some issues overnight, but regardless, the entire Northpower team - from the office-based staff to those on the front line dealing with physical component of outage restoration - have done well to get the power back on."
Mr Dawson said Northpower customers should continue to report the potential cause of power outages to the Northpower Faults line - 0800-10-40-40.
Regular outage and restoration updates can be heard on the Northpower Faults line.