Power system for high temperature applications with rechargeable energy storage

A method of fabricating a power system for a logging instrument comprising:

• selecting a rechargeable energy storage that is operable in a temperature range of between about minus forty degrees Celsius and about two hundred and ten degrees Celsius coupled to a circuit for at least one of supplying power from the energy storage and charging the energy storage;
• wherein the rechargeable energy storage comprises an ultracapacitor comprising an electrochemical double-layer capacitor comprising:
• two electrodes wetted with an electrolyte, each electrode being attached to or in contact with or coated onto a current collector and separated from each other by a separator porous to the electrolyte, wherein the electrodes comprise activated carbon or carbon nanotubes;
• wherein the electrodes, electrolyte and current collector contain less than 1,000 parts per million (ppm) of impurities, the impurities comprising at least one of halide ions and metallic species, and
• wherein the ultracapacitor exhibits a leakage current less than 1 amp per liter of volume over a range of operating temperatures and at a voltage up to a rated voltage;
• and
• a power supply;
• where the power supply is configured to supply energy from an energy storage to a logging instrument;
• a first subsystem controller;
• a first subsystem that is operative to provide a current draw for battery depassivation;
• where the first subsystem controller is configured to control the first subsystem;
• and
• an automatic bypass;
• where the automatic bypass determines a failed state for a component of the power system and reroutes power from the energy storage around the failed component;
• wherein the energy storage is configured to store between about a tenth of a joule and about one hundred kilojoules of energy, and to provide peak power of between about one watt and about one hundred kilowatts, for at least two charge-discharge cycles.