Report Number




Batteries; Photovoltaics


This report presents the initial seven-month performance summary for these 15 PV lighting systems, for the period February 13 through September 15, 1997. During this time, the systems were configured with three types of valve-regulated lead acid (VRLA) batteries (five systems using each type of battery), all operating with pulse-width-modulated (PWM) battery charge controllers. Details of the system configurations are presented in this report. Prior to initial operation, extensive baseline data was collected on the individual components installed in each system. This data included battery capacity and high-rate load measurements, battery weights, charge controller set points, PV array currents and illuminance levels. Three of the systems (one using each of the three battery types) were instrumented and outfitted with data acquisition units, for which extensive operational data were collected. Elapsed time meters were also installed in each system to record lighting load operational hours. In this report, the initial baseline data is compared to similar data collected after seven months of operation, and analyzed with respect to the continuous data collected on three of the systems. The objectives of this evaluation are to investigate the cause and effect issues of system performance, primarily those involving the performance of the VRLA batteries operating with the PWM-type battery charge controllers.

Date Published



Batteries; Photovoltaics



Rights Statement

In Copyright