Conductance is a measurement of a battery’s current producing capability. This technology can help identify batteries that have reduced performance after being in service. During the formation manufacturing process, each plate is brought to a state of 80-90% completion. This means that the electrolyte has permeated all but the center point of the plate. Incomplete formation is intentionally done to enhance shelf life as well as the battery life for the consumer.
As a result, conductance-type battery testers should never be used to determine state of health, state of charge, or Cold Cranking Amps (CCA) rating of a new, never-installed battery. New batteries will develop their full performance capability only after a period of cycling after installation.
If as an installer you wish to check the condition of a new battery prior to installation, ACDelco recommends only measuring open circuit voltage (OCV) using a high quality Digital Volt Ohm
Meter (DVOM). An OCV of 12.4 V is adequate for starting most vehicles under most conditions and the 12.4 V must be maintained during storage.
All batteries will self-discharge and deteriorate over time, therefore, proper rotation of inventory is essential.
Conductance testing of new batteries should never be used to determine the warrantable condition.
More information can be found on pages 30 to 36 of the 2014 Professional and Advantage Battery Catalogue (7A-100-14-REV).