batteries in a battery-operated smoke alarm at the beginning of a tenancy and the tenant shall replace the batteries as needed during the tenancy, except where the smoke alarm is a tamper-resistant, 10-year lithium battery smoke alarm as required by subdivision (5a) of this subsection. Failure of the tenant to replace the batteries as needed shall not be considered as negligence on the part of the tenant or the landlord.
(5a) 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 that meets the requirements provided in subdivision (7) of this section.
(6) If the landlord is charging for the cost of providing water or sewer service pursuant to G.S. 42-42.1 and has actual knowledge from either the supplying water system or other reliable source that water being supplied to tenants within the landlord's property exceeds a maximum contaminant level established pursuant to Article 10 of Chapter 130A of the General Statutes, provide notice that water being supplied exceeds a maximum contaminant level.
(7) Provide a minimum of one operable carbon monoxide alarm per rental unit per level, either battery-operated or electrical, that is listed by a nationally recognized testing laboratory that is OSHA-approved to test and certify to American National Standards Institute/Underwriters Laboratories Standards ANSI/UL2034 or