DLA 92001 (PDF)
The Capattery is a high-reliability double layer capacitor. It stores an electrostatic charge at the interface between activated carbon and an aqueous electrolyte in the so-called electric double layer. Long life is possible because the energy storage is physical rather than chemical in nature. These features also provide stable performance during extremely high shock loading.
The Capattery improves upon previous double layer capacitors because of its patented Permselective valve, which allows the escape of CO2 generated by all double layer capacitors, while it maintains its sealed construction. Being a capacitor, the Capattery requires a very simple charging circuit. It is leak-proof, exhibits no memory effect, and can deliver currents from microamps to amps. Unlike most batteries, state of charge can be directly measured.