Data Center Flooded Lead Acid Battery Early Degradation Causes, Analysis, and Mitigation

摘要

The continuous operation of the data center is very crucial as it centralizes all company's information technology operations. Due to the criticality of the equipment hosted in the data centers, their power reliability becomes of utmost importance industry wide, requiring the deployment of a big scale backup system satisfying best-in class service. In this case, the studied data center is being electrically supplied by a system of 30 Uninterruptable Power Supplies (UPS), each of which is sized to provide 750kVA/675KW of power and backed up by 7200 of flooded lead acid batteries. The whole UPS system was commissioned and put into operation in 2013. Despite that being lately commissioned, some of the battery banks have shown severe degradation and unreliability. The hasty chemical reactions, sulfation resulted in a premature aging and immediate replacement of some cells. This paper will examine the battery degradation causes and effects, as well as identify gaps between current maintenance practices and industry standards. It will also analyze battery historical data including commissioning data and battery performance test results. In addition, it will shed light on the lessons learned and the relevant cost-effective mitigation techniques implemented to overcome this issue.