Research of Asymmetric Current Charging Influence to Capacity of Storage Batteries

The problem of reducing the capacity of the battery during operation due to the appearance of a memory effect or sulfatation (depending on the type of battery and charging method) is being examined. The advantages of charging with an asymmetric current in comparison with a constant current is also being examined, based on the characteristics of the change in the capacity of storage batteries obtained as a result of experimental studies. Based on foreign and domestic(national) researches a new type of battery charger was developed. This charger allows changing the charging and discharging method depending on battery type, battery condition and user requirements. The research is aimed at studying battery batteries for a constant charge and an asymmetrical current (pulse with a reverse ejection). Analyzing changes in capacitance, changes in voltages in the time of charge and in the time of discharge of batteries. Further development of this topic can help to exceed the battery life cycle, which can directly affect the reduction of environmental pollution and reduce the cost of batteries maintenance. In the course of the experiment, characteristics such as capacity, charge current, voltage at the beginning of the charge cycle, voltage after the charge cycle (without load with connected power), voltage at the beginning of the discharge cycle (with load), voltage at the end of the discharge cycle (with load), and regression rate fixing were taken into account, depending on the number of charging cycles and further comparison of battery charging methods. The following graph shows changes in the capacity of the battery, depending on the charge cycle of the battery and the charging method, and also clearly shows the advantage of the asymmetric charging method over a constant charging method. To show that changes in the experiment for one battery can be massive the Ni-Cd, SLA batteries were considered due to their mass-production and the operational disadvantages. The charger is equipped with a system that monitors voltages and currents; responds to changes in parameters over time, works with different types of batteries and with varying degrees of battery health. The charge voltage starts to drop when the battery is fully charged and the charging current is applied to it. When the battery is fully charged, the charging power turns off and the load connects. On Ni-Cd batteries 2000mA/h, which are susceptible to memory effect, experiments of cyclic charge by asymmetric current and discharge on resistance were conducted. In the pulse, the charge current was 1A, with the discharge cycle, the battery was discharged to a 1 Ohm resistor, that gave an average discharge current of 1.2A. For Ni-Cd, the load current starts from 2 * C, where C is the battery capacity. In SLA batteries, the main problem is the reduction of capacity during plate sulfatation, experiments were performed on charge and discharge with a constant and asymmetrical current, experiments were carried out on two batteries with a nominal capacity of each 7 A/h. The charge was conducted by a constant current 1A, asymmetric with a charge pulse of 5 A. Discharge was performed using a resistive load of 15 Ohms on each of the batteries that gave an on average current value of 0.8A. For SLA-type batteries, the load current starts from 0.2C, where C is the capacity. On the basis of these experiments the reduction of capacity were concluded in both cases. However, was found that a decrease in the capacity of hermetically sealed lead-acid batteries occurs almost 2 times slower than when charged by a direct current. Ref. 14, fig. 4, photo 3.