Temperature of equipment/battery cabinets in noncontrolled environment locations in Phoenix, AZ

In the desert southwest, where summer high temperatures reach 117 to 120 degrees F in the shade, battery life and reliability is a real problem. Many outside plant equipment locations are not air conditioned and there is an abundance of Subscriber Loop Carrier (SLC) cabinets equipped with 4 strings of valve regulated lead acid (VRLA) batteries. Over the years, batteries and telecommunications equipment have failed at an extremely high rate. The problem was temperature related, but there was no efficient method to examine the environment within the cabinets. In the summer of 1993, we equipped four SLC cabinets with devices to monitor the temperature inside the cabinet and the condition of the batteries. From July 1, 1993 through September 10, 1993 we obtained the high and low environmental temperature, and high and low humidity from the National Weather Service for Phoenix, and read the cell voltage, charge temperature, and float current for each system. The purpose of the study was to determine the temperature throughout the day and night of the battery enclosure as it related to outside air temperature