Hybrid Energy Storage Based on Ultracapacitor and Lead Acid Battery: Case Study

In the following work research on lead acid battery-ultracapacitor hybrid energy storage was presented. The maximum output power and energy storage capabilities of the mentioned storage units were sufficient enough to start up an internal combustion engine of a passenger car in standard operating conditions. In the article the internal combustion engine start up process with implementation of a hybrid energy storage with battery and ultracapacitor connected in series, was analyzed. Based on conducted research it was concluded, that using a ultracapacitor and lead-acid battery in a hybrid system leads to complementation of operational parameters (i.e. high energy density and high power density is achieved) for both components in suboptimal conditions, such as low ambient temperature or low state of charge of the battery. Analysis of lead-acid battery and ultracapacitor characteristics as independent units and in hybrid configuration proved positive co-operation of both energy storage types. The research conducted presents the difference in behavior of systems based on type of ultracapacitor used in engine start-up conditions.