Battery Testing & Validation 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 Battery Testing & Validation flashcards as text
What overcharge condition does UN 38.3 Test T5 apply to lithium battery cells?
Answer: 2× maximum charge current until voltage reaches 2× maximum charge voltage or 24V
UN 38.3 Test T5 overcharges cells at twice the maximum charge current until voltage reaches twice the maximum charge voltage or 24V, whichever is lower, to evaluate safety margin.
What is the purpose of a battery crush test in safety validation?
Answer: Evaluating the cell's response to mechanical deformation that may cause an internal short circuit
Crush testing mechanically deforms the cell to simulate physical damage and evaluates whether the resulting internal short circuit leads to fire, explosion, or thermal runaway.
In a charge retention test, what is being measured?
Answer: Percentage of initial capacity remaining after a defined storage period
Charge retention tests measure the fraction of initial capacity recoverable after storing a fully charged cell for a defined period (commonly 28–90 days) at specified temperature and SOC.
What does the Peukert effect describe in battery testing?
Answer: The relationship showing higher discharge currents yield lower effective available capacity
Peukert's law describes how a battery's effective available capacity decreases as discharge current increases, due to higher internal resistance losses and limited ion diffusion rates.
Which test verifies battery performance under realistic dynamic load profiles representative of electric vehicle operation?
Answer: Dynamic Stress Test (DST) or drive-cycle profile test
Dynamic Stress Tests apply variable current profiles derived from actual vehicle drive cycles, better replicating real-world usage than constant C-rate testing.
What does a post-test teardown and failure analysis of a cycled battery cell examine?
Answer: Physical and chemical changes to electrodes, electrolyte, and separator to identify degradation mechanisms
Post-test teardown involves disassembling cycled cells to analyze electrode morphology, lithium plating, separator condition, and electrolyte decomposition products to understand degradation root causes.
What is thermal runaway characterization testing designed to determine?
Answer: The onset temperature, propagation behavior, and severity of thermal runaway events
Thermal runaway characterization identifies trigger temperatures (T1, T2, T3), propagation rates between cells, and gas and heat release to inform safety design and hazard classification.