Keywords: power back-up, battery monitoring, valve regulated lead acid batteries, VRLA batteries, coup de fouet, distributed intelligence, wireless communications, embedded systems
New approaches in battery monitoring architectures, design and methodologies
The typical dilemma of a backup battery system user is whether to rely on the guarantees of a battery supplier with regard to product performance, or to independently monitor battery status to ensure reliable backup power when the power is needed. This dilemma has created a vague sense of mistrust between battery suppliers and end users. More and more end-user decision makers, however, are leaning toward the use of monitoring devices to 'guarantee the power they need, when they need it'. This trend can have positive benefits for all concerned, as end users become better educated about the values and uses of monitoring technology. Once an end user has decided that monitoring is a good decision, three questions arise: what to monitor, how to monitor it and how to get 'the most for the money'. These questions have become very important issues in today's battery user marketplace. This paper will discuss a number of different monitoring criteria, their utility for the end user and their effect on the battery supplier. Field data will be presented as practical examples. The paper will then focus on today's new approaches to system architecture and system design, and new measurement methodologies for determining important parameters not monitored by traditional field devices. The primary new contributions are the application of distributed intelligence, wireless communications and embedded systems to battery monitoring, resulting in an order of magnitude cost reduction and increase in end user functionality (see Section 4.1). Finally, the relation between data obtained through the monitoring process and the battery system's status will be discussed, with an attempt to derive a basis for user-friendly criteria in the selection of monitoring equipment and the utilisation of monitoring test results.