ABSTRACT
The power source of an underwater vehicle is the main component that determines its range of travel and the tasks that it can perform. Until recently, the choice of practical power sources for most applications was limited to lead-acid and silver-zinc batteries. Lead-acid batteries are a well-established technology and are available at low cost. However, they have a low energy density (~25 Wh kg-1). Although silverzinc batteries have a much higher energy density (~120 Wh kg-1), they are expensive, and have a short life of 40-100 cycles compared to 1000 cycles for lead-acid (Carey et al., 1992). There is, in practice, no all-purpose, ideal choice of power source for an autonomous underwater vehicle (AUV). Developers have sought to use a variety of battery types including nickelcadmium, nickel-metal hydride, lithium ion and primary manganese alkaline and lithium cells, often using stacks of cells developed for the consumer or industrial markets.
