Charging system utilizing excess grid electricity

A charging system, for charging electric vehicle batteries using an electrical grid, having three live conductors and one neutral conductor, the electrical grid having a grid usage level, a peak usage level, and a grid capacity, comprising:

• a current sensing unit having an inductive loop that is adapted to encircle one of the live conductors, designated as a charging live conductor, such that a sensed current is magnetically induced in the inductive loop in proportion to electricity flowing through the charging live conductor;
• a step down transformer having a primary input adapted to connect to the charging live conductor and the neutral conductor, and a secondary output selectively connected to the battery chargers through their associated charging relays;
• a plurality of stages connected to the secondary output, each stage having a battery charger, each battery charger adapted to connect to and charge one of the electric vehicle batteries, each stage further having a charging relay having poles and a coil, the poles of the charging relay selectively connecting the battery charger to the live conductor, and a controller connected to the sensed current and having an enabling output connected to the coil of said relay, the controller providing an enabling output to energize the coil and disconnect the charger from the live conductor when the sensed current reaches a predetermined threshold, wherein the predetermined threshold for each of the stages is different so battery charging occurs on all of the battery chargers when grid usage level is low and that the battery chargers associated with the different stages are consecutively deactivated as the grid usage level increases.