If we had a battery then obviously we have to buy a battery charger to charge our battery again and again.
But if you want to purchase a factory-made battery charger then it costs you very much.
This battery charger circuit is automatic which means when your battery gets full the circuit automatically auto cut the charging process.
What is Automatic Battery Charger?
Simply a charger charges the battery constantly whereas the battery gets full for not. But in the automatic battery charger, the charging process is automatically cut off when the battery gets fully charged.
In the circuit of an automatic 12-volt battery charger, we use an op-amp ic that is Lm358.
We also use a 12-volt relay to cut off the charging process when the battery gets fully charged.
1) LM 358
2) 3x1k, Resistance
3) 2x 10k potentiometer
4) 6v Zener Diode
5) 2x 1n4007 Diode
6) 2x Led
7) 12v Relay
8) BC547 Transistor