Simulation and modeling of battery chargers/maintainers

Battery maintainers are widely used in marine and ground vehicles whose batteries have cycles of operation involving long periods of non-active life. Durability of such batteries, without proper maintenance, does not exceed one year. Extension of the battery life-time requires very thorough monitoring and periodic, preferably automatic recharging to replenish lost charge due to battery selfdischarge and external loads. Due to complex technical and environmental conditions, the battery chargerslmaintainers must satisfy very strict requirements what complicates processes of design. During the designing phases of battery maintainers, very thorough modeling and simulations are very important. It is necessary to include variable charging strategies, environmental issues, and the character of charged batteries. The paper discusses modeling and simulation of two major generic types of battery chargerslmaintainers. One type supplies the battery with constant current, another operates under constant charging voltage conditions. In both cases, the battery voltage and temperature must be monitored to define the best conditions for evaluation of the end of charging phase. In the paper, the results of simulations for the above battery maintainers are presented. Analog and digital control of charger/maintainer structures are presented.