How to Charge 12V Car Battery with 19V Laptop charger | DIY Car Battery Charger

In this video you will see a very simple way how to charge a 12 volts car or a motorcycle battery with 19 Volts laptop power adapter (laptop charger)
Difference between 19 and 12 voltages drops on a light bulb, I've used 12 volts 21 watt light bulb.
If you need higher current use two 21W bulbs in pararel, or you can use just one 55W light bulb.
Important: Charging will NOT stop automatically even if battery become fully charged, so you need to disconnect charger manually when a battery reaches 14.2 volts, or when cells of the battery starts to release hydrogen.
Do you have any questions? ask in the comments below.
In the future, you can just get a cheap car battery charger here:
Amazon: amzn.to/2ZDhuaV
AliExpress: s.click.aliexpress.com/e/_ASxsPH

[@iceho6460]

I used this method and it worked. I only charged the battery up to 13.6V, the voltage then drops down to the normal resting voltage of 12.6V. This method saved me from buying an immediate replacement battery, and a dedicated battery charger, or the possibility of having to call for an emergency jump start service. Thank you for the video.

[@estinordaugusma6704]

Brilliant it works, my battery died after I left it in the for 2 months. I charge using this method only light bulb and 19 volt laptop charger. After an hour I start the car with the battery

[@michaelmanguba6930]

This Technic,just saved my butt ..that's a lot ..it really works

[@jerryguellang2037]

5yrs ago na video mo tol pero sobrang sulit at nashare mo d2, so helpful

[@JuaNers0n]

Thank you very much. Greetings from Venezuela.

[@y0uormygmail]

What an awesome mind, my car battery are charging right now by my laptop charger! will install it 2morow and see if it going to hold back again.

[@peterjames37]

Thanks, you are a genius. I did the project with 2 light bulbs in parallel. I used it on a battery that was very old and dry as a bone. I filled it up with distilled water and a bit of liquid from another battery. I hooked it all up and it started to charge the battery. At first, the light bulbs didn't go on at all. But as time went on they started to glow a bit and the voltage started to go down from 19v to 17v. The power adapter started to get a little warm as the glowing increased, but not hot. I then swapped the adapter for an actual battery charger and the battery started to charge. Awesome video. Thank you very much.

[@valdomirosilva4127]

Thank you very much, it works very well. I'm from Brazil !

[@danankblast]

Oh my god its work! i use asus laptop adaptor and 12 volt 35watt bulb♥️♥️♥️♥️ very thx,, my car finaly start again,

[@wahidgm9605]

Oh my battery is charging 🙏💕 thank you so much I sub

[@GOLDENWORKSTV]

Awesome Sir! BEst Regards from GOLDEN WORKS TV.

[@robdejesusii5830]

How did I not see this?? I knew there is a way aside from those ludicrously priced battery chargers and then you happened. Thanks so much! Will try it this coming weekend. Been worrying about my battery as I don't have time to go out and have it charged somewhere due to bad weather. Hopefully this can help me solve the problem and hopefully finally let me have a home battery charger! 😍

[@thekiller7622]

Does it work or will it affect the battery or the charger?

[@KevinCoisy]

I've improved the system a bit i've put a powerful headlight lamp and a weak one in parallel, when shorting the + and - both lamp work, but when plugged to my discharged battery only the weak lamp lights up ! Meaning the powerful one will light up when the battery is gonna be charged. Thanks for the tutorial even with electrical knowledge you sometime need a heads-up ! Great channel !

[@vcutDIY]

Impressive, using bulb as a resistor,. Brilliant

[@VINCEPARK]

Can I use 24v ? And do it like that to charge my car battery ?

[@shinehead9303]

Thank you very much, it really works.

[@ffreportgaming456]

I have 19.5 volt and 7.7amp adaptor. so i will use 12 volt 35watt bulb use this adaptor. Plz plz answer me.

[@LHTD_YT]

I have a question: do you need to plug in the battery?

[@remigior.palmerojr.8406]

Sir can i ask..what bulb you usef at your video? I mean what is that watts your bulb you use??

[@fadereal1]

Great video..Thank you so much..!

[@marklesterlim922]

Thank you so much,it's working!!!!

[@misterfrediemcfullvlogs2715]

Thank you for the content that share it useful for me

[@coreyfellows1945]

Got a link to the digital volt meter … that’s cool

[@ankitmudgal23]

Great man.. is it necessary to add bulb in series

[@sowjanyadevarakonda2396]

How u increased charging current? I mean u said by adding load..?but do current flow be effected by adding load? U kept 12V bulb & droped ,doesn't the overall voltage is Lesss than the charging voltage range like 14V to 15V

[@callistusjoseph6388]

Good idea & simple. Thanks

[@ISSO8BOITE]

Every battery car or some special batteries with open /close cells ?

[@orzorz2218]

why use lamp? for reduce voltage or amper? if i have 19v adaptor with 0.5 amper do i nedd lamp? thanks

[@deepakmanda71]

can we simply use a 35 ohms resistance instead of bulbs

[@BoggsOliver]

Thank you very much more diy videos to come..,..

[@babetosaid5180]

hi. can i charge deep circle battery 170ah with this method? yellow cable from your bulb is negative right? thanks

[@ElectricalPro]

Hi, Yes, you can. No, yellow cable from the bulb is positive (plus). Black cable from the charger is negative (minus).

[@victorangelobarte8560]

Thanks bro my car battery is charging

[@governmentxx1896]

Thank you so much for teaching me something I really appreciate you 1:24

[@ack0011]

Would a LED diode work instead of a light bulb? i have a bunch

[@breantharveyeljoedette8078]

HI, i just watch your video, i have a set of battery for my ebike 48v20Ah, when its full charge it will be 52 to 53v on my lcd, but lately, i charge it then my charger gets green, when i check my lcd its still the same but when i run my ebike, it just fall fast unto 42.7v that causes my ebike to crawl. when i check the batterys individualy (12v each set of 4) one of the batterys line just got burned due to the wire was jam. so im asking if i can do these procedure like on your video to fully charge my batterys? hope youl read my comment and help me thank you....

[@marlonalbarracin3845]

i all ready try this, but when i connect it to tha battery the bulb light up even though the charger is nor plug in. is rhat ok?

[@rogerburnett1013]

My alternator and battery charger is down and on a small island in the Caribbean there's no replacements due to pandemic. This idea has saved the day and has enabled my 50 year old Land Rover to start, make a trip into town and get me home again. I've taken the ammeter off my defunct battery charger and wired it into the circuit. With a 40W bulb I'm charging at 2.5amps.

[@ZazerZazetty-ib8rg]

قصتك جميلة في البحر الكاريبي ....تمتع

[@euripides4733]

Ingenious way of using existing hardware 2 solve y'r problem, BTW.. my damn laptop charger (TUM-90WAUT) (9.5-22V; 5A max outp.((90W)), shouldn't need this, should by its own downrate itself, but only after adding the serial resistor of the lamp switches to 12 Volts, ripping my hair out.. any idea?

[@andymcgee5110]

Dude you are a King Boss! Thank you for this video. Would this work as an adequate power source for an electrolysis tank? Since it wouldn't be used to charge a battery would I really need to use a light bulb? Could I just run the negative straight to my piece being cleaned and the positive straight to my sacrificial anode?

[@kylekeeper4111]

i didnt try yet, but i thibk will work. thanks in advance.

[@arunasjaspelkis6982]

I have one question. Currenly have laptop charger from premium class notebook. 19.5V and 12A (o think it 230W is ti gona work wih bulk lamo, to dcrease currency?) planning to charge to batter battery is 100ah. One camples , can i dro curenvy wiih potenciomert?

[@tkhiam9184]

From now on, m saving a lot of time, money and energy! Now I have one engineering degree!! 😎😎

[@dl7423]

have the following: 15v 3a charger with battery voltage currently at about 12v ... what is the 12v light bulb wattage range to use? thanks

[@jesusmariarodriguezolivarr2477]

You do not use a bulb, conectalo directo.

[@sajithm.s3344]

Very useful video thanks..

[@paulna5526]

ok, I've read a lot of your replies so I'm going to assume it's just better to use the 18.5 V or 19 V charger with a light bulb, which gives out about 1.5 amps, that seems to be the best way of doing it. so guess you won't have to answer this if you prefer not to, but thanks for putting this info on you tube. it's great.

[@ElectricalPro]

Yes, you are correct. Here is one more way to explain why we need a light bulb: a charger and a power supply actually are two different devices. A battery charger limits current, but a power supply doesn't limit current at all, and that is why we need a light bulb. Moreover, in order to fully charge a battery, we'll need to reach 14.2V on its terminals, which is impossible using a 13.5V power supply. Anyways I am glad that you find my video useful.

[@sohildeshmukh3733]

Can I use a 12V - 1.0A charger without any parallel

[@joaobatistadeoliveiraolive5316]

Very Good from Brazil

[@witek3437]

I think you can use a potentiometer instead of a light bulb and check the voltage with a meter. Am I right? And can I charge the batteries eg 3V or 6V with this power supply?

[@ElectricalPro]

Hi, yes, but you'll need a very powerful potentiometer. Depending on a desired current you will need a 10W or maybe even 60W potentiometer. For a 6V motorcycle battery I think it is better to use a 12V power supply, it will be more energy efficient. But please DON'T charge Li-ion batteries with this method, because they may explode.

[@miguelruiz2782]

Exelente video brother thanks

[@omkarpatil4916]

I have 12v 5 a charger. Can i contact it directly to battery without bulb please reply

[@ronissac9828]

Can i connect two 6V bulbs in series to get the resistance of 12 V bulb

[@xsauce3858]

Yea

[@sanjugoudar]

How much time it takes for full charge?

[@DanSoussi]

I like your videos. Here is a comment that I share. All the energy through the light bulb is effectively wasted as heat, probably around 50% of the power from the power pack. Would it be not better to introduce a low cost buck converter ( under $10) to change the 19.5V to 12V, at an efficiency of typically 85-90%? The benefit of the buck converter will be to significantly reduce the emitted heat and charge your battery nearly twice as fast, too.

[@dakshithanissanka2361]

Why did you leave the cell caps open while charging?

[@SPICEVlogPh]

thanks for sharing video i want to make this

[@winnerdata1237]

GREAT VIDEO

[@camiloa.francop.5714]

Hello, I have a 19V laptop power supply and a 21W bulb, I have been charging the battery during all the day but the battery between its poles does not pass above 12.30V. Any suggestion?

[@farrukhaleem8893]

battery is probably damaged.

[@andisadler2897]

So if i had 14v laptop charger i wouldnt need a light bulb would i?

[@oo3962]

Nice !!! Keep up the good work !!!

[@shajik.damodaran8156]

Hi bro, can I charge 12v maintenance free battery of my bike with this method ? Thanks.

[@esperanzaruales8655]

Hi can i use 12v led? I don't have a bulb

[@mixstuffin]

i did same, but my battery charging is below 1volt, so can i do the same to get charged, but bulb connected in series not getting blow and voltage at battery terminal is 19 volt, please help

[@mark5432]

Can i use a 21 Watt 12volt car lamp bulb?

[@urchmanogboo6265]

does the bulb need to light when chargeing and how long is it going to stay to charge fully

[@ElectricalPro]

Hi, yes, the bulb needs to light when charging, and the brightness of the light will become lower and lower throughout the charging. Charging time will depend on many things, like the capacity of the battery, and how deeply it is discharged, and also light bulb effects charging time, a more powerful bulb will make charging faster. The best way to tell whether the battery is fully charged or not is to measure the voltage while the battery is charging. If the voltage becomes higher than 14.2V the battery is fully charged.

[@masterflickmusic8010]

Very helpful

[@ozgur.ruzgar]

Adaptör gücü kaç olmalı en az ? 60 A aküyü kaç saat şarj etmek gerekir bu şekilde ?

[@2dabang]

I have a question: I replaced a car battery recently as it was 3 years old and could not start the engine. I checked the voltage using a multimeter and it showed 10.45 Volts. Does it mean the battery is quite dead and cannot be charged?

[@ElectricalPro]

Just try to charge it, 10.45 Volts just means it is discharged. If it is a new battery just from a store it is not good, because storing discharged battery is bad for the battery.

[@narutokun291]

what if I use a 12 volt wifi adapter? can it charge my battery?

[@408DJGUERO]

Help me! So the laptop charger can charge batteries directly!? I have three 6 volt batteries that I will connect them series to produce 18 volts, that laptop charger which is about 18 volt itself will charge them from end-to-end correct? Also if I added 1/4 battery to get 24 volts will the charger be sufficient and work properly? Thanks

[@ElectricalPro]

To fully charge a 12V battery you'll need 14.2V, therefore for a 6V battery, you will need 7.1V, but since you have 3 of them connected sequentially you will need 21.3V for a full charge. So 19V Power supply will not be enough. Moreover, to charge a battery you will need some kind of current limiter, in the video, I've used a light bulb for such purpose.

[@jbnrusnya_should_be_punished]

Непогано. Але вони кажуть "negative" та "positive", це в нас тільки плюс та мінус. Що plazma - ще жива чи нє? В мене A-Mega 7 Ultra 2016 ще жива.

[@joannahuff6276]

So, what to do with the negative wire, my lights won't light up unless i connect a negative to it

[@vinceorosco360]

can i use output 20v?

[@paulna5526]

can I use a 13.5 computer charger rated at 3.5 amps, without putting in the bulb???

[@user-bf6dp4os8x]

your computer charger will be damaged bruh

[@shirazahmed9912]

Hi...can i use 100 watt bulb??

[@pdengineer9047]

If I don't have the right light bulb, can I use resistors in series?

[@ElectricalPro]

Hi, yes you can, but you will need a lot of resistors to make 6W or even 12W in total.

[@babetosaid5180]

thanks will give a try

[@dibyajyotimohanty6371]

Can I jump start with this?

[@spiritme6047]

Great video, wish I m that knowledgeable:) I do have a pet project where I will need to charge a small 12v battery (10amps, I think, the small bike battery) many times a day. Is there a technique I can use in keeping it on charge continuously without checking up on it for overcharging. I believe solar charging should deploy such tech, but I don't have any idea what it is.

[@paulkansteiner5392]

I would charge that 10 amp battery at around 1 amp or less. But to be able to leave it on all the time, it would be good to have an inexpensive battery minder so it shuts off when the battiry is fully charged. Ive had a Schauer on a huge battery for about 3 years.

[@AI5G]

Thanks , m doing it now

[@ssikarim]

Thanks

[@pointdss]

this guy sounded like a Tesla Tank in Red Alert 2 - Yuris Revenge XD

[@larryarce8698]

cool game butt not cool🖕🏻 thats my brother

[@larryarce8698]

hi luis is that the same thing you did last time

[@saqibrehman4701]

Dear this will work on bike battery?? I tried it but bulb didn't turn on,so that is why now change in the volts, stays at 19v. Why the bulb is not turning on??

[@helloengineer324]

How to Watt this bulb (light)

[@rvlin4740]

Thanks man..

[@johncalvert5700]

Well that was cool but not what I seached for, lol I want a 12v laptop charger. 😅

[@geetadhunnoo7466]

It works thank you

[@ricardogerber6371]

Hi there. I have the suply of 19v 3.72amps laptop charger ..and I used a dual wire bulb with a wattage of 5Watt 12V and What is the thickness that the wire must be or is it okey if the wire stays cool cause I have a 0.5mm wire for the stream

[@ricardogerber6371]

And I dont have the multimeter so I dont know if my charging current is enough can you please reply a.s.a.p

[@ElectricalPro]

Hi, If you use 5 Watt 12V bulb then the charging current will be less than 0.5A, I think your 0.5mm wire will handle such current fine, but a thicker wire is better of course. Thicker wire can handle much more current. The thicker wire you use the cooler it will be.

[@otiplacyendor8672]

How many amps is your laptop charger??? And when you connect the light bulb it reduces amps as well???

[@ElectricalPro]

Hi, my laptop charger can provide 3.16 Amps (max). Yes the light bulb limits current to 1.2A - 1.8A, but if you use more powerful light bulb the current will be higher.

[@furulevi]

What would happen without the bulb?

[@omnnykynng944]

I would like to know what what would happen if you don't use the bulb

[@kemar1385]

Yea what would happen with out the bulb and cant u just use the loptop charger to just start the car

[@lowcostdiy9594]

the buld reduce the adapter output from 19v to 12v

[@zappertxt]

I believe there'd be a risk of damaging the battery and producing dangerous fumes. At worst, it may explode or leak acid. But that'd be extreme.

[@benedictearlson9044]

This will work without a bulb but you need to charge for short bursts of time eg 5-10mins to avoid overheating the battery. Your 12v battery should take 19v for short periods with rests in between to allow for cooling. Aim to get enough juice into it to get your car started then allow the battery to fully charge on the car with all unnecessary accessories off (eg lights, radio, fans) to avoid straining your alternator. I just charged mine straight (positive to positive etc) from a 19v 3.42amp laptop charger for a total of 35mins over several charges and it started the car no problem. Only issue was the charger itself was making a whining noise so it could be damaged but it was a spare so be aware you could shorten life of your charger or cause it to overheat. Take suitable precautions against acid and explosions, monitor battery and charger, I accept no liability if you follow this advice and are injured or there is damage.

[@andrzejwojcik3892]

THANKS HELP

[@Prashugarage]

Car car amplifier or stereo 1 aisi video banao Jaise Ye Dono cheez chahiye with laptop charger 19 volt

[@mojoman7459]

Hi @Electrical projects, i have 19.5v charger and 12v 35w bulb. Can I use it to charge a 65A battery. Battery is currently having only 8v showing.

[@smoke_stackz3168]

Your battery must be broken. To old.sulfated cell.or dried up cell

[@andreika6681]

if you have a modern battery you'll need a special a special desulfatation charger (it does high freq higher voltage (30-40v) cycles to make the electrodes to vibrrate and unclog 'em) to bring it back to life and it may cost more than the price of a new battery. they use 'em in specialised centers where it's economically justified to do it on dozens of batteries. DIY it'd be complicated... and it'd take like 2-3 days...

[@smoke_stackz3168]

@@andreika6681 but modern batteries when it discharge it for too long the positive plates get worn out got broken sometimes i charged my batteries with desulfator

[@syedelham7281]

Hi there! Tried the same technique but for some reason, the bulb does not light up in this particular circuit. When I connect the bulb separately in power socket it lights up and when the same thing is connected to the circuit, nothing happens. Any advice on what I might be doing wrong?!

[@SuperThembanator]

You have to connect the light bulb only to the positive side of the battery and the other end must be connected to the charger in series

[@mizisport9090]

maybe because the voltage go thru the bulb 7v so not enough, or +ve side of bulb must connect with +ve side of charger and -ve side of bulb connect with +ve side of battery due to current flow.

[@ack0011]

could you use something other than a light? like a 12v fan?

[@ElficGuy]

Yes

[@xsauce3858]

Can I use a 120W laptop charger ?

[@briedas87]

simple explanation, just what i was looking. thanks

[@jhongrey3685]

Hi.. I have a 32 and 16v printer adapter can I use it?

[@ElectricalPro]

Theoretically yes, but not like in this video. It will be difficult, because 32V is too high so you will need to connect bulbs sequentially, which is not good. 16V looks good, but if you use a 12V bulb, the charging current will be too low, so you will also need to figure out how to make it work well. But the most important that I know nothing about how much current your power supply can provide, so it is hard to tell at all.

[@ibrahemahmed8883]

hi.... thanx for the vedio please i want to charge battery 12v-100am so how many bulb i need??? or one bulb 12v- 200w good for charge???

[@ElectricalPro]

Hi, Yes, one bulb 12V 200W is good. But, before charging make sure that your power supply can provide 10A of current. If your power supply cannot provide 10A, then you need to use less-powerful bulb.

[@CrazyCoupleDIY]

Good work bro

[@isronenermy585]

thanks