Battery arrays, rechargable Li-ion battery power sources for marine applications

The design of battery systems for marine devices has become very complex with the introduction of rechargeable lithium-ion battery technology. In the past, battery technology such as sealed lead acid was fairly simple to design into a system. Battery cells could be strapped in series and parallel to achieve the desired voltage, current and total capacity. This is not possible with rechargeable lithium-ion technology, as the charge and discharge of each cell needs to be carefully monitored and controlled to keep the devices safe. Lithium-ion cells provide some of the highest energy density of any high volume battery technology as well as a very low cost as the technology is driven by notebook computer industry. This paper describes a new patent-pending technology that allows system designers to build lithium-ion battery systems using off the shelf pre-engineered components. The system uses small lithium-ion smart battery packs and combines them into groups of any size to create very large battery power systems. The technology scales from a few battery packs to hundreds of packs. This technology is being used in AUV and UUV designs as well as buoys and other marine and nonmarine devices. A family of DC-DC converters can provide high power regulated output voltages from 33V to 144V for directly powering user devices. "Battery Clusters" can be configured to fully charge in under two hours, in place with a simple two wire DC charge voltage input, or they can charge from weak sources such as solar panels, wind generators or water turbines.