A 24-volt direct current battery charger can be used to recharge a 24-volt battery, or it can be used to recharge two 12-volt batteries at the same time. To construct one of these chargers will require a step down transformer. It is used to reduce the 120-volts alternating curent of an outlet down to a 24-volt AC level. This current is then fed through a rectifier which converts the AC to DC for charging the batteries.
Secure the transformer to one end of the 2-inch by 10-inch block. Connect a power cord to the two primary terminals of the transformer. This will allow the transformer to get power from a wall outlet.
Secure the bridge rectifier to the wood block. Position it 3 to 4 inches away from the transformer. Cut two 5-inch black wires and strip 1/2-inch insulation from the ends of both wires. Connect one end of the first black wire to one of the 24-volt terminals on the secondary side of the transformer. Connect the other end to one of the two AC terminals on the bridge rectifier. Then connect the second wire to the second 24-volt terminal and the second AC terminal on the rectifier.
Cut one 5-inch red wire and one 5-inch black wire. Strip 1/2-inch insulation from the ends of both wires. Connect one end of the black wire to the negative terminal of the bridge rectifier, and connect one end of the red wire to the positive terminal of the bridge rectifier.
Place two large screws at the far end of the wood block. These screws should be spaced about 5 inches apart. Connect the other end of the red wire to one screw, and connect the other end of the black wire to the second screw. These two screws serve as the terminal connections for the battery charger.