From the Apartment Association of North Carolina:
The North Carolina General Assembly this week ratified a bill that modifies state Landlord-Tenant law by calling for tamper-resistant,10-year Lithium Battery Smoke Alarms to be installed in certain, limited circumstances. The duty to install such an alarm is limited to when new alarms are installed or when replacing existing alarms (not merely when replacing batteries in existing alarms). The Apartment Association of North Carolina did not oppose this bill. The key new language:
The Landlord shall, after December 31, 2012, when installing a new smoke alarm or replacing an existing smoke alarm, install a tamper-resistant, 10-year lithium battery smoke alarm. However, the landlord shall not be required to install a tamper-resistant, 10-year lithium battery smoke alarm as required by this subdivision in either of the following circumstances:
a. The dwelling unit is equipped with a hardwired smoke alarm with a battery backup.
b. The dwelling unit is equipped with a smoke alarm combined with a carbon monoxide alarm.
Link to the complete Ratified Bill: http://www.ncga.state.nc.us/Sessions/2011/Bills/Senate/PDF/S77v5.pdf