How to Make 6V Lead Acid Battery Charger

Introduction: How to Make 6V Lead Acid Battery Charger

About: Share diy projects to those who have the same hobby with me

Hii friend,

Today I am going to make a circuit of 6V Lead acid battery charger without using transformer.

Let's get started,

Step 1: Take All Components As Shown Below

Components required -

(1.) Polyester capacitor - 105J 250V x1

(2.) pn-junction diode - 1N4007 x4

(3.) Resistor - 390K x1

(4.) Resistor - 1K x1

(5.) LED - 3V x1

(6.) Lead acid battery - 6V x1

(7.) Connecting wires

Step 2: Connect All Components

Solder all components according to the circuit diagram.

Step 3: Solder 390K Resistor

Firstly we have to solder 390K resistor to both pin of polyester capacitor as solder in the picture.

Step 4: Make a Bridge Rectifier

Next make a bridge rectifier like as picture.

Step 5: Connect Rectifier to Capacitor

Next Solder Bridge rectifier to the capacitor as you can see in the picture.

Solder rectifier according to circuit diagram.

Step 6: Solder 1K Resistor

Next we have to solder 1K resistor as solder in the picture.

Step 7: Connect 3V LED

Now we have to solder an LED.

Connect -ve pin of LED to 1K resistor as shown in picture.

Step 8: Solder Input Power Supply Wire

Now solder Input power supply wire.

We can give 240V AC (50/60 Hz) Input power supply to the circuit.

Connect Phase wire to capacitor and neutral wire to rectifier as solder in the picture/shown in the diagram.

Step 9: Connect Battery

Now connect battery to the circuit as connected in the picture/circuit diagram.

Step 10: Solder +ve of LED

Next solder +ve of LED to the +ve of Battery.


Give power supply and left it upto 2-3 hours for charging and use this lead acid battery.

NOTE : For constant output DC Power supply connect an Electrolytic capacitor to the Polarity of Battery.We can use capacitor 50V 100uf , 25V 1000uf.

PRECAUTION : This circuit is very dangerous so be careful during the experiment and Don't try to touch circuit when power supply is on.

Thank you

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    Tip 1 year ago

    Aside from "don't touch the circuit" -- don't touch the battery, or anything vaguely connected to it, this whole circuit is considered at hazardous mains potential.

    This style of transformerless power supply should be treated with suspicion and respect :) They are usually used in entirely contained projects, where there are NO external connections accessible at all.

    The capacitor you have used is inappropriate. You say this is for use with 240V AC, however the capacitor you show is 250V working. The peak value of the mains in normal operation is well over 250V, never mind peaks and surges. So it should be higher voltage working.

    It looks like an ordinary polyester cap. Look up Class-X and Class-Y capacitors, these are designed for use in these positions, and are designed to fail safe. Normal capacitors are not.

    Please add a fuse in line with the incoming live mains!

    Your designations for the polarity of the four diodes (bridge) are confused: The symbols |>| are correct, but the extra "+" and "-" are the wrong way round. Remove them. Same for the LED.

    Lastly: Lead Acid batteries should be charged at VERY clearly limited constant voltage, any higher and they just start to bubble away hydrogen. Even the "sealed" ones. This will destroy them. You absolutely MUST find a way to limit the voltage accurately as per the battery spec.