A New Concept: Intermittent Charging of Lead Acid Batteries in Telecommunication Systems

Present communication systems operate their batteries in a full float mode. This mode provides a constant charge voltage which is sufficient to maintain the batteries in the fully charged state. However, this charge voltage causes an increased rate of positive grid corrosion - the accepted life-limiting failure mode of lead acid batteries. The new concept reduces the time the batteries are on float and, as a result, extends the life of the battery. This is accomplished by maintaining the batteries at their open circuit potential for most of the time and then periodically recharging them. This paper also describes a system that has been developed to provide for intermittent charging and to test each battery string, on a monthly basis, to assure proper battery availability.