A battery charger is disclosed for use with various batteries, such as automotive and marine-type batteries. In accordance with an aspect of the invention, the charging current is alternated between non-zero DC charging current levels. By alternating the charging current between non-zero DC charging levels, the battery can be charged to a higher capacity (i.e., ampere hours) faster, thus reducing the charging time and at the same time allow the rating of the battery charger to be increased. In accordance with another important aspect of the invention, the technique for alternating the charging current can be implemented in both linear and switched-mode battery chargers.