An intrinsic self-charging biosupercapacitor built on a unique concept for the fabrication of biodevices based on redox polymers is presented. The biosupercapacitor consists of a high-potential redox polymer based bioanode and a low-potential redox polymer based biocathode in which the potentials of the electrodes in the discharged state show an apparent potential mismatch E-anode > E-cathode and prevent the use of the device as a conventional biofuel cell. Upon charging, the potentials of the electrodes are shifted to more positive (cathode) and more negative (anode) values because of a change in the a(ox-)to-a(red) ratio within the redox polymer matrix. Hence, a potential inversion occurs in the charged state (E-anode < E-cathode) and an open circuit voltage of >0.4 V is achieved and the bio-device acts as a true biosupercapacitor. The bioanode consists of a novel specifically designed high-potential Os complex modified polymer for the efficient immobilization and electrical wiring of glucose converting enzymes, such as glucose oxidase and flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase. The cathodic side is constructed from a low-potential Os complex modified polymer integrating the O-2 reducing enzyme, bilirubin oxidase. The large potential differences between the redox polymers and the prosthetic groups of the biocatalysts ensure fast and efficient charging of the biodevice.