Development of VRLA battery capacity estimation system

NTT Facilities, Inc. has developed a valve regulated lead acid (VRLA) battery capacity estimation system. The system is composed of capacity test equipment, capacity evaluation equipment, a data transfer program, a central database and a regression curve generating program. The system can transmit data (on battery capacity and internal resistance) from a battery´s location to a central database over an intranet. We periodically use the newest data on the database to remake a regression curve for a given battery. This curve is sent over an intranet back to the site where the battery is located to provide maintenance staff with the latest regression curve available. The staff can then estimate battery capacity with an error of less than 10% using the updated regression curves, which compares favorably with the previous error rate of 30% using the conventional method to estimate battery capacity.