FR Supercapacitors KEMET FR Supercapacitors offer a 5.5VDC operating voltage (maximum) and operate in a wide temperature range of -40°C to +85°C. These maintenance-free modules are also known as electric double-layer capacitors (EDLCs). KEMET FR Supercapacitors are designed to be highly reliable against liquid leakage and are RoHS compliant. Typical applications include a secondary battery when applied in a DC circuit and low-voltage DC hold-up applications such as embedded microprocessor systems with flash memory.