Influence of temperature during formation of lead acid AGM batteries on chemical and electrical performance

One of the most critical processes in the production of lead-acid batteries is the electrochemical formation of the plates. In the case of VRLA (valve-regulated lead-acid) batteries with glass mat separators, this process is carried out post-assembly, after the plates are sealed in the battery casing and sealed with a lid. AGM (absorbed glass mat) batteries are initially filled with electrolytes and placed in water baths, where the formation process begins. The use of water baths is essential for temperature control, due to the highly exothermic nature of the formation process. Temperature management during formation is a key factor due to its impact on several key parameters, including PbO₂ conversion factor, water loss, and potential degradation of additives, such as lignosulfonates, in the plates. Excessively high temperatures can adversely affect the integrity of these additives, negatively impacting battery performance and life. The presented research focuses on the effect of temperature during the formation process on the basic electrical properties of AGM batteries and the chemical properties of the positive and negative plates after this stage. The research aimed to optimize the formation process in order to increase process efficiency.