Charge Your Car Battery With Laptop Charger!


Introduction: Charge Your Car Battery With Laptop Charger!

About: I am a 15 y/o kid who loves to work with electronics,Opening all Old Things at my home,Making portable speakers. JAI GURU JI

Hey Guys Whats Going On?
In This Instructable I am Going to Show You How To Charge Your Car Battery With A Laptop Charger.
This Method Is Unsafe But It Can Be Used In Emergency,Takes 3-4 Hours Though.!
This Method worked out well For Me!
Make Sure To Watch My Youtube Video As Well(BIG GIVEAWAY AT 1K SUBSCRIBERS)



For This Project We Are Going to Need A Few Things
2)Digital Multimeter
3)Digital Voltmeter
4)Jumper cables(Wires would work but jumpers would be safe)
5) Laptop Charger(10-17v only.)

Step 2: Wiring!

Now You Need To Follow This Schematic Diagram And Start Charging the Battery
To Be More Safe I Crimped Off The DC jack From The Laptop Charger Though You Can Still Use The Dc Jack As It Is,The Outer Metal surface is negative whereas the Small Hole Inside The Dc Jack Is Positive!
The Reason That the positive Wire Is Going through multimeter is because by that it will show us the current reading on multi meter!

Step 3: Noting the Current!

Now Our Car Battery Is Charging!
Keep Noting the current and the Voltage!

Step 4: Testing!

Now After 4 hours Of Waiting, The Voltage of the battery was near 12.3
I hooked it Up With My Car And Tested It
And YES it started to see the car starting just visit my youtube video embedded in Introduction!
Make Sure To Subscribe Me On Youtube As I will Do A Giveaway



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    10 Discussions

    Actually, you can charge even with 19V laptop charger if you add lighbulb.

    I understand that the multimeter here is measuring the current flowing into the car battery, but can you explain what purpose this information serves? Simply knowing what the current is may not by itself have any bearing... Unless it does somehow. And if so, can you explain it? In other words, if I do NOT use a multimeter to measure the current btw the laptop adapter and the car battery, what will I be missing? (esp. given that I know the adapter can't put out more current than the battery can hold, just more voltage, which I am already measuring through the volt meter attached to the car battery in your design). Thanks!

    How does a car do it. I.e. stop over charging?
    Actually I'll Google it later.


    2 years ago

    What is the unsafe issue? Is there a risk damaging the battery due to the little to high voltage?

    1 reply

    Yes,We Need To Keep A Check On The Voltage! It Shouldn't exceed 12.6.

    Yes, sometimes we do have to take chances to deal with unexpected tasks, but we try and do it with some risk factor control. Rather than letting this thing run free and unfettered, it would be wiser to hook up a timer so it can only be run in say 1 hour intervals, forcing a restart, this would ensure close monitoring of the situation. I am not opposed at all about what you have presented, just wanted to introduce a safety net is all.

    1 reply

    You Are Absolutely Correct! That Way It Would be more safer.
    I Will Work On That!

    The risk is overcharging the battery. When this happens the battery will produce more (explosive) gas and eventualy be damaged. Use only for emergency and keep monitoring not only the current but the voltage of the battery to not go over 12.68 volts while charging. (the voltage depends on exact type and make of the battery) The current will be limmited by the powersuply, so that will not be the biggest issue.