According to the Do It Yourself website, a DC battery charger can be made by combining a power bulb base, a silicon diode, insulated wire, a connector and a AC to DC converter. These parts should be assembled together correctly for the charger to be able to send AC power to a DC source.
A power supply, such as a wall socket, is normally run on AC charge. This charge is different from DC charge in that it is not portable and remains in the position that it is in throughout its lifetime. AC and DC are similar and can be exchanged with the use of a converter. For the converter to work properly, the voltage that is contained within the AC source should be compatible with the voltage that is being directed toward the DC source. The purpose of the DC charge is that it is of lower density and does not have as high of voltage as AC, making it safer for portable use.
The wire that is being used for the conversion of AC to DC power sources should be copper wire. This ensures that the power from the silicon diode and the converter is correctly distributed throughout the entire charger. This power goes through the light bulb base as well and is the basis for charging the DC voltage that is directly connected to the battery.