NABCEP Battery Storage Systems & Energy Storage 2

Question 1

In an AC-coupled battery storage system, the battery inverter connects to which bus?

Accepted Answer

The AC electrical panel or AC bus

Answer

In an AC-coupled system, the battery inverter connects to the AC bus, meaning solar energy is first inverted to AC before being re-converted to DC for battery charging.

Question 2

Which NFPA standard specifically addresses the installation of stationary lead-acid and lithium-ion battery systems in commercial buildings?

Accepted Answer

NFPA 855

Answer

NFPA 855, Standard for the Installation of Stationary Energy Storage Systems, provides requirements for battery system placement, separation, fire suppression, and hazard mitigation.

Question 3

What is 'cycle life' as applied to battery storage systems?

Accepted Answer

The number of complete charge/discharge cycles before capacity falls below a specified threshold

Answer

Cycle life is the number of full charge/discharge cycles a battery can undergo before its usable capacity degrades to a defined percentage (commonly 80%) of original rated capacity.

Question 4

Which lithium battery chemistry is most susceptible to thermal runaway if overcharged or mechanically damaged?

Accepted Answer

Lithium nickel manganese cobalt oxide (NMC)

Answer

NMC (lithium nickel manganese cobalt oxide) chemistry has higher energy density but is more prone to thermal runaway compared to LFP, which has superior thermal and chemical stability.

Question 5

What is the primary safety concern when installing flooded lead-acid batteries in an enclosed indoor space?

Accepted Answer

Hydrogen gas off-gassing during charging creating explosion risk

Answer

Flooded lead-acid batteries release hydrogen gas during charging, which is explosive at concentrations above 4% in air, requiring adequate ventilation per NEC and manufacturer requirements.

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

(NABCEP) Certified North American Board of Certified Energy Practitioners Specialist Practice Test

NABCEP Battery Storage Systems & Energy Storage 2