12v 7ah Battery Charger Circuit Diagram Pdf



Simple 12 volt battery charger circuit diagram designed by using few easily available components, and this circuit is suitable for different types of batteries needs 12 Volt. You can use this circuit to charge 12V SLA battery or 12V Gel cell battery and so on. This circuit is designed to provide charging current upto 3 amps and this circuit don’t have reverse polarity protection or over current protection so kindly test this circuit before stepping into battery charging.


For safe working and to avoid overcharging of battery, absorption voltage is selected as 14.1V and floating voltage is selected as 13.6V. These values are to be set as specified by the battery manufacturer. 12V battery charger circuit Fig1: 12V battery charger circuit. Circuit diagram of the 12V battery absorb and float charger is shown in Fig. Nov 02, 2017 12v Battery Charger Circuit. 12v 7ah smart battery charger with pcb simple 12 volt circuit lead acid detailed project 100ah diy solar inverter 24v diagram arduino controlled wiring. To maintain a battery you can use a Trickle 13.2V up to 500mA, a Battery Tender with Hysteresis Threshold 12.6V – 14.5 V up to 1.5A, and a Smart Battery charger up to 20A, with equalizing and battery reconditioning feature. Buy at Freight Harbor Tools, a Battery Float Charger, Automatic on sale for $9.99 or ($6.00 with coupon). In this case the charger will add to the output and deliver some current to the load while charging the battery. If you are charging a flat cell, the current should not be more than 100mA. For a 7AH battery, the current can be 500mA. And for a larger battery, the current can be 1Amp.

This Simple 12 volt Battery Charger Circuit Diagram gives you a outline design for the general battery charger and you can add additional features to this circuit like reverse polarity protection by placing a diode at the output. (Diode anode to output positive supply and diode cathode as output positive terminal) and over current protection setup using transistors. The following charger circuit just a Raw prototype to give 12 Volt output to battery.

Circuit Diagram

Components Required

  1. Step down transformer (0-14V AC / 3 Amps) – Choose depends on your requirements.
  2. Bridge Rectifier module BR1010
  3. Capacitors 0.01µF, 100µF/25V each one
  4. Resistor 1KΩ (Use 0.25W for normal LED)
  5. LED

Construction & Working

Use Required ampere Step down transformer for your target battery, here we have used 0-14V AC / 3 Amps Step down transformer and for AC to DC rectification we have used Bridge Rectifier module BR1010 which gives High efficient DC supply with high Current rating.

BR1010

This Bridge Rectifier module will have four terminals, two for AC supply input noted with sign wave and two terminals for DC output noted with positive and negative sign.

C1 and C2 capacitors are performing as filter in this circuit then LED indicates the presence of DC power supply at the output. Connect the target Battery at the output to get charged.


The set up makes it possible to make an simple 12V battery charger of excellent level of quality through which you are able to recharge batteries of 1 2 Volts for car, and dry batteries employed in the systems of alarms.

Its functioning seemingly automatic considering that, whenever it's plugged into a battery, it will eventually only function if the battery is discharged, and it is going to automatically remove when the battery is fully charged.

The unit is driven by a transformer whose secondary is usually 14-15 Volts having a current of 3 Amperes minimum.

The trimmer TR1 is tweaked to ensure that at the output of the battery charger there exists a voltage of about 14.4 volts without load.

The absolute maximum distributable current is 3 Amperes, so DO NOT make an effort to recharge batteries with a capacity higher than 36Ah. Best utilization of this device would be to power a battery charger for alarm system with battery in standby mode.

Diy 12v Battery Charger Circuit

In the course of installation, attention should be taken to hook up the battery with the proper polarity.
For the construction of the components, cautiously stick to the configuration of the diagram.

Printed circuit, AUTOMATIC BATTERY CHARGER INPUT 14-15 VOLTS at a charging CURRENT of MAX 3 AMPERES

12v 7ah Battery Charger Circuit Diagram Pdf

12v 7ah Rechargeable Battery

Parts List for the 12V automatic car battery charger circuit:

All resistors are
Of 1/4 watt unless otherwise specified.

12v 7ah Battery Charger Circuit Diagram Pdf

Rl-470 Ohms
R2 = 10 K
R3 = 270 Ohms
TR1 = 10 K trimmer.
Cl = 1000uF25V.
DZ1 = 5.1 volts lWzener.
T1 = 2N2218
T2 = 2N3055-BDW21C
1C1 = UA741
PT1 = KBL04 / 01
1 Socket 8 pins.
1 Heat sink for Tl.
1 Heat sink for T2.

Simple 12V Battery Charger with Battery Indicator

This is a simple 12V battery charger circuit with indicator circuit is a smart charger circuit. You are able to ideally take advantage of this circuit for applications such as inverters, portable chargers, etc. This design additionally includes a twin indication system in the form of a battery charging indicator, and a low battery buzzer indicator. The benefit of this indicator is that a buzzer notifies you once the battery has to be recharged. This circuit design undoubtedly aids for your daily life battery charging purposes.

How the simple battery charger circuit works
- The charging circuit is created around voltage regulator IC 7815 and a couple of BC transistors 547 BJTs.
- The main 230V or 110V input could be the first steped down through a step-down transformer, after that it may be rectified and filtered.
- This DC voltage is then delivered to the voltage regulator IC 7815 ;. The output gets regulated at 15V
for charging the connected 12 volt rechargeable battery at the output of the voltage regulator. And it begins charging the battery as soon as the main power is available.
- Any time battery voltage falls under a particular value LED1 ceases to glow and the buzzer begins sounding indicating that the battery is discharged and requires recharging.

12v 7ah Battery Charger Circuit Diagram Pdf System

Bill of Material
-transformer (230V to 15V or 110V T0 15V)
-pont rectifier (1N4007 x 4)
-condenser (470UF, 50V)
- IC 7815 Voltage Regulator
-12V rechargeable battery





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