12V Battery Charger Circuits with Auto Cut-off

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Introduction

Power up your batteries like a pro with these Simple 12V Battery Charger Circuits with Auto Cut-off! Are you tired of dealing with dead car batteries or alarm system batteries? We bring you two easy-to-build circuits that will charge and protect your batteries from overcharging. These circuits are perfect for those who want a high-quality battery charger that is both efficient and automatic.

We are sure you’ll love these Simple 12V Battery Charger Circuits with Auto Cut-off! Say goodbye to dead batteries in your car or alarm system with these easy-to-build circuits that will charge your batteries safely and automatically. With these great circuits, you can charge your batteries and take your power supply to the next level.

Circuit 1: Simple 12V Battery Charger

Hardware Required

S noComponentsValueQty
1ICUA7411
2Capacitor1000uF
25V
1
3ResistorRl-470 Ohms
R2 = 10 K
R3 = 270 Ohms
1
1
1
4Zener Diode5.1 volts1
5V. Resistor10K1
6TransistorT1 = 2N2218
T2 = 2N3055-BDW21C
1
1

Circuit Diagram

Working Explanation

The first circuit is an automatic 12V battery charger with an auto cut-off feature that can recharge car and dry batteries used in alarm systems. The circuit is powered by a transformer with a secondary voltage of 14-15V and a current of 3A minimum. A trimmer is adjusted to achieve an output voltage of 14.4V without load. The maximum distributable current is 3A, so batteries with a capacity higher than 36Ah should not be charged.

Circuit 2: Simple 12V Battery Charger with Battery Indicator

Hardware Required

S noComponentsValueQty
1Voltage RegulatorLM78151
2TransistorBC547P2
3Resistor10k, 1.5k, 100k1, 1, 1
4Diode Bridge1N40071
5Diode1n41481
6Zener Diode9V1
7Buzzer1
8V. Resistor4.7K1
9Capacitor470uF
50V
1
10Transformer230V to 15V1
11LED1
12Battery12V1

Circuit Diagram

Working Explanation

The second circuit is a simple 12V battery charger with a battery indicator circuit. It is designed using a voltage regulator IC 7815 and two BC transistors 547 BJTs. The primary input voltage is stepped down by a transformer, rectified, and filtered before being regulated at 15V by the voltage regulator IC 7815. The battery starts charging as soon as the main power is available. The circuit has a twin indication system with a battery charging indicator and a low battery buzzer indicator. When the battery voltage falls below a certain value, the LED stops glowing, and the buzzer starts sounding to indicate that the battery is discharged and requires recharging.

Final Thoughts

In conclusion, these Simple 12V Battery Charger Circuits with Auto Cut-off are an excellent choice for anyone who needs a reliable and efficient battery charger. The circuits are easy to build and come with clear instructions and a parts list, so you can start building right away.

So, go ahead and try them out for yourself, and see how they can make your life easier and your projects more efficient!