Effect of Inventory Storage on Automotive Flooded Lead-Acid Batteries

The battery is a central part of the vehicle’s electrical system and has to undergo cycling in a wide variety of conditions while providing an acceptable service life. Within a typical distribution chain, automotive lead-acid batteries can sit in storage for months before delivery to the consumer. During storage, batteries are subjected to a wide variety of temperature profiles depending on facility-specific characteristics. Additionally, batteries typically do not receive any type of maintenance charge before delivery. Effects of storage time, temperature, and maintenance charging are explored. Flooded lead-acid batteries were examined immediately after storage and after installation in vehicles subjected to normal drive patterns. While phase composition is a major consideration, additional differences in positive active material (PAM) were observed with respect to storage parameters. Batteries stored in a hot environment and kept at constant float voltage for a significant duration exhibited favorable PAM characteristics relative to other storage environments. In all cases, batteries kept on float charge throughout storage exhibited favorable PAM characteristics relative to batteries stored under equivalent conditions on open-circuit charge.