Practice Test Geeks(BMS) Battery Management System Certification Practice Test
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Architecture & Functional Components Flashcards

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

Read the first 7 Architecture & Functional Components flashcards as text

  1. Which BMS topology places cell-level monitoring ICs directly on each cell group without a central master controller?

    Answer: Distributed architecture

    In a distributed BMS, slave ICs are mounted close to each cell group, reducing wiring harness length and improving measurement accuracy.

  2. What is the primary function of the pre-charge circuit in a BMS output stage?

    Answer: Limit inrush current when charging large capacitive loads

    The pre-charge circuit uses a resistor and relay to slowly charge the DC bus capacitors, preventing high inrush current that could weld the main contactor.

  3. In a BMS with daisy-chain communication, what happens if a single slave node loses power?

    Answer: All nodes downstream of the failed node lose communication

    Daisy-chain topologies route communication sequentially, so a failed node breaks the chain and isolates all downstream slaves from the master.

  4. Which component within a BMS slave IC is responsible for converting analog cell voltages to digital values?

    Answer: Analog-to-digital converter (ADC)

    The ADC inside the slave IC samples each cell's analog voltage and converts it to a digital word that the master controller can process.

  5. A BMS uses isolated CAN bus for internal communication between master and slaves. What is the main reason for the isolation?

    Answer: To prevent ground loops and protect low-voltage electronics from high-voltage pack potentials

    Galvanic isolation prevents dangerous high voltages on the battery stack from propagating to the vehicle's low-voltage control network.

  6. Which passive balancing method dissipates excess cell energy as heat through a resistor?

    Answer: Resistive bleeding / shunt balancing

    Passive (resistive) balancing switches a bleed resistor across overcharged cells, converting excess energy to heat to equalize the pack.

  7. What does the 'cell supervision circuit' (CSC) typically measure in a multi-cell BMS architecture?

    Answer: Individual cell voltages and temperatures

    The CSC (slave board) monitors per-cell voltage and temperature, feeding that data to the master BMS controller for state estimation and protection.