A non-aqueous electrolyte secondary battery has a positive electrode having a positive electrode collector, on which a positive electrode active material layer containing a positive electrode active material as a complex oxide of Li and transition metals are formed, and a negative electrode having a negative collector, on which a negative electrode active material layer is formed. It is advantageously applied to oil-water mixtures under high pressure andor temperature. A low resistance driver circuit regulates power supplied from the super-capacitors to the load.