If the storage volume of the PxtFX is not sufficient, the device with the designation PxtEX comes into play. A single PxtEX can store two, four or six kilowatt seconds of energy with its aluminum electrolytic capacitors specially developed for the application spectrum of active energy management systems. Simply connected to the PxtFX via cables with connectors that are protected against reverse polarity, the storage extension directly benefits the system. The individual storage units are internally protected and indicate their charge level visually via a flashing LED. Integrated into the PxtEX as standard is also a safe discharge resistor, which directly and quickly helps to bring the entire system to a voltage level that is safe for humans. In principle, however, Koch systems are low-maintenance.