Automated Battery Charger Instrumentation Interface for Multiple Interconnected Battery Strings as a Student Project

The goal of this project was to create a remote monitoring and control capability for the eight large battery charging units currently in use at the Naval Acoustic Research Detachment in Bayview, Idaho. These units charge 1866 valve regulated lead acid batteries that provide power for propulsion, instrumentation, and control of the second Large Scale Vehicle (LSV 2), a Navy acoustic research submarine. These batteries must be charged while the submarine is dry docked with each of eight battery groups connected to its own independent charging unit. Charging consumes up to eighteen hours and requires constant monitoring by a battery technician. To allow for increased control of the inputs, students designed a remote control capability utilizing an incumbent government-approved, but unused and poorly documented, hardware interface within the chargers. The students verified data collection from existing sensors and formatted it within the charger’s architecture. They then transmitted the data to a computer workstation and stored and displayed it in a nearby office area. They implemented a government-approved algorithm to generate input commands for the chargers through their custom-designed graphical user interface. RS-232 serial communications presented these commands to the charger for automatic implementation. As required, a human operator verified the loop, comparing commands to resulting voltage and current readings. Initial testing of the prototype showed communications were established with Charger #1. Subsequent designs, accomplished as a follow-on project for a graduate student, completed the interface for the remaining chargers. This paper describes the design process, including both hardware and software design, as well implementation and testing, performance results, and recommendations for further improvement.