Does improper selection of filter capacitors on the BMS control board lead to insufficient suppression of interference in specific frequency bands?

Improper selection of filter capacitors is a common cause of insufficient interference suppression in specific frequency bands. Capacitors have impedance-frequency characteristics and exhibit equivalent series inductance (ESL). Large-capacity electrolytic capacitors have low impedance at low frequencies but high ESL and low self-resonant frequencies. Above MHz, they exhibit high impedance due to their inductive properties, failing to filter out high-frequency noise. If high-frequency characteristic MLCC capacitors, such as 0.1μF, are not used for decoupling, high-frequency noise cannot be suppressed. Correct selection requires using multiple capacitors in parallel, such as a 10μF electrolytic capacitor for low frequencies and 0.1μF and 0.01μF MLCCs for mid-to-high frequencies, to cover a wide bandwidth and ensure low impedance at the target suppression frequency.