This is a design of the circuit diagram of a simple and straight forward battery charger that can be used to charge all type of 12V rechargeable batteries including car batteries.
This circuit is completed with ammeter VU for displaying the current. This is the figure of the circuit.
The circuit is nothing but a 12V DC power supply with an ammeter for monitoring the charging current.
The two diodes forms a centre tapped full wave rectifier. The capacitor filters the rectifier output to produce a clean 12V out put.
At initial stages of charging the ammeter will read about 1 to 3 amperes. As the battery is slowly charged the current slowly decreases.
For indicate when the battery is fully charged, the ammeter reading will be zero. For attention, it is always be careful to connect the charger to the battery in correct polarity.
The polarity is connecting between positive to positive and negative to negative.