Practice Test Geeks(NABCEP) North American Board of Certified Energy Practitioners Solar Practice Test
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Energy Storage Flashcards

7 cards from real NABCEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Energy Storage flashcards as text

  1. What is the primary purpose of a battery management system (BMS) in a lithium-ion energy storage system?

    Answer: To monitor and protect individual cells from overcharge, over-discharge, and thermal events

    A BMS monitors cell voltages, temperatures, and currents to protect lithium-ion cells from conditions that could cause damage or safety hazards.

  2. A battery bank has a usable capacity of 20 kWh and a maximum continuous discharge rate of 5 kW. What is the C-rate at the maximum discharge?

    Answer: C/4

    C-rate = discharge power / capacity = 5 kW / 20 kWh = 0.25C, which equals C/4.

  3. Which battery chemistry is most susceptible to thermal runaway and requires the most stringent safety controls?

    Answer: Lithium nickel manganese cobalt oxide (NMC)

    NMC lithium-ion batteries have higher energy density but are more prone to thermal runaway if overcharged, over-discharged, or physically damaged.

  4. In an AC-coupled energy storage system, where does the battery inverter connect?

    Answer: On the AC bus, parallel with the solar inverter and loads

    In AC-coupled systems, the battery inverter connects to the AC bus, allowing it to charge from both the solar inverter output and the grid.

  5. What does 'round-trip efficiency' measure in an energy storage system?

    Answer: The ratio of energy delivered by the battery to energy required to charge it

    Round-trip efficiency is the percentage of energy recovered from storage compared to the energy put in, accounting for losses in both charging and discharging.

  6. A lithium iron phosphate (LFP) battery system is rated at 10 kWh with 80% depth of discharge. What is the usable energy capacity?

    Answer: 8 kWh

    Usable capacity = total capacity × DoD = 10 kWh × 0.80 = 8 kWh.

  7. Which NEC article primarily governs the installation of energy storage systems in the United States?

    Answer: Article 706

    NEC Article 706 specifically addresses energy storage systems, covering installation, disconnecting means, overcurrent protection, and wiring methods.