A capacitive system includes a module circuit card assembly including a first modular keying and alignment mechanism and a second modular keying and alignment mechanism. The first and second modular keying and alignment mechanisms are configured for mechanical alignment and electrical connection with a backplane circuit card assembly (CCA). A capacitor is mounted to the module circuit card assembly and is electrically connected to each of the first and second modular keying and alignment mechanisms through a charge/discharge circuit. The circuit is configured to: charge the capacitor with the module circuit card assembly connected to the backplane CCA, discharge the capacitor with the module circuit card assembly connected to the backplane CCA for providing backup power, and discharge the capacitor through a bleed resistor of the circuit upon disconnection of the module circuit card assembly from the backplane CCA.