Comprehensive noninvasive battery monitoring of lead-acid storage cells in unattended locations

The authors describe how a four-year R&D effort has successfully culminated in field trials of a prototype, noninvasive Pb-acid wet-cell battery monitoring system. Parameters measured include: voltage; (charge) maintenance current; internal temperature; electrolyte fluid level; reservoir specific gravity; (rated) current-path integrity; and electrode utilization (state-of-charge) for all cells plus current, voltage, and temperature for the overall bank. The system employs multi-sensor cell-monitor modules affixed to each cell which transmit condition data via fiber-optic cable to a supervisory bank monitor. As many as 256 cells can be supervised per bank monitor, and an unlimited number of bank monitors can be supervised by a (remote) centralized PC employing modems and public telephone lines. The PC can periodically interrogate all active bank monitors, download and process stored data, and archive and display both state and trend battery-condition information down to the level of individual parameters on individual cells