Introduction: 4V Lead Acid Battery Charger

Picture of 4V Lead Acid Battery Charger

MY First Instructables Friends ,

So this is for those who are new to Lead Acid batteries and about charging them , A cute Little 4V battery charger

SO What we need to charge a 4V Lead acid battery, all we need is A 5V regulated supply, and let's make it ......


1. 5V Voltage Regulator ..... ----- I.e . Ls7805

2.Header Pins Or anything you want to use to connect the battery to circuit

3. 1N4001 rectifier Diode

4.An ECB, Or breadboard or anything like that........

Step 1: The Circuit

Picture of The Circuit

First you need a DC power source Which Is Greater than 7Volts for the battery charger to work correctly, you can attach a laptop charger with a dc jack , or you can also use a set top box Adapter. and at the output of voltage Regulator connect the battery

Circuit is In the pictures


My Other Projects

1 Wireless Electricity Module

2 .Function Generator

3. JTAG ICE with Arduino IDE

4. Getting Started With JTAGICE Clone


Step 2: FINISHED ............

Picture of FINISHED ............

don't mind about the capacitor, it in not used in circuit............


aravs1 (author)2017-09-14


I have a confusion, please tell me max voltage of 4V Sealed Lead acid battery and also specify minimum voltage of battery.
thanks in advance.

_Boltz_ (author)aravs12017-09-14

these batteries works on the same voltages as other lithium ion phone batteries..... and can be charged with a compatible charger ... so min voltage is around 3.6 - 3.7V and max voltage is 4.2 to 4.3V. hence using a diode after 7805 will further step down voltage to 4.3V.

rakeshe1 (author)2016-09-29

How much time this circuit would take to fully charge battery

_Boltz_ (author)2015-11-11

actually the best solution for these batteries are those li-po or ni-cd battery chargers

ryuhemanth (author)2015-11-10

I think , charging voltage per cell should be 2.3V to 2.45V and a charging current of c/10.

so for a 4V 500mAh battery it should be 4.6 to 4.9 @ 50 mA . I have Sunca 4v 1000mAh and i am looking forward to make a charger.

yogeshwara (author)2015-05-01

Cnt we just use a 5v adapter and a diode to charge it ???

_Boltz_ (author)yogeshwara2015-05-09

and yes , yogeshwara, you can ,but with a ressistor. in series...

_Boltz_ (author)2015-05-03

and let me remind you.....more the current will be (greater than 41.6%) more is the possibility of damaging the battery.... for limiting the current you can use a resistor .

_Boltz_ (author)2015-05-03

actually the indicator is a problem for mee to (Actually I am working on it..)..... but you can check the status of battery by measuring the voltage by voltmeter the voltage of a fully charged battery is 4.2V , and never use a power supply of more than 41.6% current of that of the capacity of battery else it will cause the sulphuric acid inside to boil.... that's the reason why I am working on a newer version..... it would be coming soon.... by the end of may....

yogeshwara (author)2015-05-01

Cnt we just use a 5v adapter and a diode to charge it ???

yogeshwara (author)2015-05-01

How to know when it is fully charged

_Boltz_ (author)2015-03-28

An update is coming soon my friends

About This Instructable



Bio: + A Maker, With Big Dreams And right Tools to accomplish them. + Let's Make this World A Positive place to live, Either by wish and ... More »
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