Development and Experience of a Practical, Pressure-Tolerant, Lithium Battery for Underwater Use
For a number of years, lithium-ion batteries have promised energy and power densities that make them an attractive alternative to the silver-zinc batteries historically used in underwater vehicles. For AUV (Autonomous Underwater Vehicle) application, polymer-electrolyte cells offer the promise of pressure tolerance; this key attribute impacts vehicle design and operational logistics in a number of ways. Primarily, it facilitates the design of arbitrarily large battery packs by obviating many of the problems associated with large, heavy and expensive pressure vessels that would have been otherwise required to house batteries at depth. This allows a single AUV operator to recover the vehicle and remove and replace the batteries in minutes without the down time associated with servicing o-rings and seals. In a military context, this new operational paradigm has made back to back search and classify missions a practical reality. As with all new technologies there is a hiatus between availability, practical implementation and adoption. Many fundamental, logistical and practical engineering problems in design and manufacture have been solved in the past 5 years leading to a range of commercially available batteries with power densities exceeding 100Wh per neutrally buoyant Kg. This paper will explore these challenges, examining specific solutions derived from experience gained through the pressure testing of over 20,000 cells
Integration of pressure-tolerant lithium ion battery modules within the Mola Mola AUV
Battery aging coupled with additional loads placed on the power system of the Mola Mola AUV required that the original battery pack be replaced with a higher capacity system. A set of requirements were assembled to ensure the new pack would be electrically compatible, safe, and of appropriate configuration for AUV use. Pressure tolerant SeaSafe lithium ion modules, produced by the Southwest Electronic Energy Group, were selected for the new power system. Two of these modules connected in series produce a nominal 59 V and capacity of 1.6 kWh to provide adequate energy for the medium-sized AUV. A pressure-balanced oil-filled housing was built for the modules, along with interface electronics and connectors. The additional electronics are used to switch power to the vehicle, to allow connection to an external charger, and to direct serial communications from the batteries to either the vehicle or charging station.
The Hollywood War Machine: U.S. Militarism and Popular Culture
CONTENTS Preface Chapter One: Media Culture in the Imperial System Chapter Two: Militarism in American Popular Culture Chapter Three: War and Cinema: The Historical Legacy Chapter Four: The Vietnam Syndrome: Politics and Cinema Chapter Five: Recycling the Good War Chapter Six: Cinematic Warfare in the New World Order Chapter Seven: Hollywood After 9/11