500 homes are still without power
Overhead power cables were worst affected by the ice-storm
About 500 homes in Northern Ireland are still without power, Northern Ireland Electricity has said.
The company has said it is hopeful all customers will back on supply by midnight. It has restored electricity to about 99,500 homes.
NIE has also fitted small generators in 60 homes since Tuesday's snow storms.
It has done so for customers who rely on electricity for their healthcare needs such as dialysis machines, ventilators or nebulisers.
About 400 people on NIE's critical care list were affected by power cuts.
One of the electricians working in the Ballymena area, Stephen Greer, said he had been averaging about four hours sleep each night.
"Between this weather and my five-week-old daughter, I've only been managing a few hours sleep each day.
"Keeping these generators going means that I'm revisiting homes twice and sometimes three times a day to check them and top them up with fuel.
"Once mains power is restored, we need to safely remove the generator, switch customers back on and take the generator to the next person that needs it."
Most of those customers still affected on Sunday were in north and east County Antrim.
Ballymoney Council's assistance centre at the Joey Dunlop Leisure Centre remained open until 1800 BST on Sunday to provide hot food, showers and shelter.
A relief centre was also running at the Millennium Centre in Loughguille, but it has now closed.
Earlier NIE said almost 650 staff have been working on Easter Sunday to restore power. They include 295 workers from the Irish Republic, Isle of Man and Scotland.
