How to Charge 12V Car Battery with 19V Laptop charger | DIY Car Battery Charger
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- เผยแพร่เมื่อ 12 มิ.ย. 2024
- 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 - วิทยาศาสตร์และเทคโนโลยี
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.
Thank you very much. Greetings from Venezuela.
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
This Technic,just saved my butt ..that's a lot ..it really works
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.
Thank you very much, it works very well. I'm from Brazil !
Oh my battery is charging 🙏💕 thank you so much I sub
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.
قصتك جميلة في البحر الكاريبي ....تمتع
5yrs ago na video mo tol pero sobrang sulit at nashare mo d2, so helpful
Awesome Sir! BEst Regards from GOLDEN WORKS TV.
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.
Thank you very much, it really works.
Impressive, using bulb as a resistor,. Brilliant
Oh my god its work! i use asus laptop adaptor and 12 volt 35watt bulb♥️♥️♥️♥️ very thx,, my car finaly start again,
Great video..Thank you so much..!
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! 😍
Does it work or will it affect the battery or the charger?
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 !
Thank you for the content that share it useful for me
Thank you so much,it's working!!!!
Thank you very much more diy videos to come..,..
Good idea & simple. Thanks
Got a link to the digital volt meter … that’s cool
Very Good from Brazil
Thank you so much for teaching me something I really appreciate you 1:24
Can I use 24v ? And do it like that to charge my car battery ?
Thanks bro my car battery is charging
Very useful video thanks..
GREAT VIDEO
I have 19.5 volt and 7.7amp adaptor. so i will use 12 volt 35watt bulb use this adaptor. Plz plz answer me.
Exelente video brother thanks
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?
i didnt try yet, but i thibk will work. thanks in advance.
Very helpful
this guy sounded like a Tesla Tank in Red Alert 2 - Yuris Revenge XD
cool game butt not cool🖕🏻 thats my brother
hi luis is that the same thing you did last time
thanks for sharing video i want to make this
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
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....
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?
why use lamp? for reduce voltage or amper?
if i have 19v adaptor with 0.5 amper do i nedd lamp? thanks
Nice !!!
Keep up the good work !!!
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?
From now on, m saving a lot of time, money and energy!
Now I have one engineering degree!! 😎😎
Can i connect two 6V bulbs in series to get the resistance of 12 V bulb
Yea
Sir can i ask..what bulb you usef at your video? I mean what is that watts your bulb you use??
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.
have the following: 15v 3a charger with battery voltage currently at about 12v ... what is the 12v light bulb wattage range to use? thanks
You do not use a bulb, conectalo directo.
hi. can i charge deep circle battery 170ah with this method? yellow cable from your bulb is negative right? thanks
Hi, Yes, you can. No, yellow cable from the bulb is positive (plus). Black cable from the charger is negative (minus).
I have a question: do you need to plug in the battery?
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?
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?
battery is probably damaged.
Every battery car or some special batteries with open /close cells ?
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
Would a LED diode work instead of a light bulb? i have a bunch
So, what to do with the negative wire, my lights won't light up unless i connect a negative to it
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?
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.
Great man.. is it necessary to add bulb in series
can we simply use a 35 ohms resistance instead of bulbs
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.
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.
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.
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.
Hi, nice video, which size of resistor I can use instead of right bulb? Thanks please reply.
You can try for example 10 Watt 10 Ohms. But such powerful resistor is not easy to find, that is why I've used a light bulb. With 10 Ohms, the current will be less than 1A. For the higher current you will need even more powerful resistor, with lower resistance... for example 20 Watt 5 Ohms.
@@ElectricalPro Thank you for fast reply, how about using inductor instead of bulb?
It is not a good idea. Well, if it is 5 Ohms and can handle 2 - 3 Amps then maybe yes... but in this case, we don't use it as an inductor, we use it as a resistor. The only reason why inductor may work is because it uses a lot of wire, and wires have some resistance, therefore in some cases inductor may work as a resistor. But finding such inductor is even more difficult than finding a resistor.
@@ElectricalPro Thanks, I get you.
thanks will give a try
What would happen without the bulb?
I would like to know what what would happen if you don't use the bulb
Yea what would happen with out the bulb and cant u just use the loptop charger to just start the car
the buld reduce the adapter output from 19v to 12v
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.
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.
That's great. I have a query:
When I test voltage on CHARGING mode, it shows 14.2v, and when switched off the CHARGING, it shows battery voltage 12.x volts not 14.2v now. Here you have said to keep the charging till 14.2v battery voltage - Now this voltage you have said is while CHARGING or CHARGING disconnected?
There's a difference of about 14.2v - 12.6v=1.6v when charging is off. Obviously on charging it shows 1.6v more than actually battery voltage. I am using 12v 21w bulb and 65W laptop charger with output of 1.xAmp
Hi, 14.2v is while charging (charger connected). When it reaches 14.2v while charging you can consider it fully charged, and you can disconnect the charger. Usually, it slowly drops to 13.0V, but I think 12.6V is fine.
@@ElectricalPro Thanks. I got it. I think 12.70v is default we get newly from market. so 12.6v is fine. But finally it dropped to 12.3v which shows the battery is holding 50-70 charge.
Maybe not all of the cells are equally charged. Maybe "equalizing charge" is needed, but I am not sure.
@@ElectricalPro Thanks once again for your response. Yeah I also think that all cells are not charged equally but I had to close the charging as it was reached to 14.6v and battery was showing 12.8v means it was reached to full charging level. But as voltage is dropped from 12.8 to 12.3v I believe it is no more holding the charging equally to all the cells. But it's running fine on 12.3 also and my car run daily so let's see how far the battery goes.
I have 12v 5 a charger. Can i contact it directly to battery without bulb please reply
Thanks , m doing it now
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
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.
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?
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.
Can I use a 12V - 1.0A charger without any parallel
can I use a 13.5 computer charger rated at 3.5 amps, without putting in the bulb???
your computer charger will be damaged bruh
Thanks man..
Well that was cool but not what I seached for, lol I want a 12v laptop charger. 😅
Good work bro
Why did you leave the cell caps open while charging?
It works thank you
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?!
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
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.
So if i had 14v laptop charger i wouldnt need a light bulb would i?
1:26 Be carefully, because the diagram on the right is may be wrong, looks this type of chargers have 3 pins: outer cylingdical shell is minus, innher cylingdical shell is plus, and pin in the center is data pin, that is used by laptop to speak with charger brick and detect its power limit, that is why when you connect not supported power supply (for example: 40W charger instead of 60W one), it will write a notification and will not charge the laptop. At least my Dell laptop charger has this pinout.
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??
I have same materials even 19v 3amp supply but with mine i still havw 19 volt after bulb
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
And I dont have the multimeter so I dont know if my charging current is enough can you please reply a.s.a.p
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.
simple explanation, just what i was looking. thanks
Hi bro, can I charge 12v maintenance free battery of my bike with this method ? Thanks.
THANKS HELP
Thanks
does the bulb need to light when chargeing and how long is it going to stay to charge fully
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.
Super 👌
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???
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.
How many amps is your laptop charger??? And when you connect the light bulb it reduces amps as well???
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.
hi can i charge car battery using that charger you made and what happens if i overcharge my car battery....it is free maintenance battery and i have 19.5v dc output dell laptop charger with 3.34amp, can i use 35w bulb? pls reply thank you...
Hi, car batteries are pretty tolerant to overcharging, so nothing will happen if you overcharge it, but it's better not to overcharge it too much or too often. Yes, a 35w bulb will be fine for your car battery. (but it will be too much for a motorcycle battery).
I have had a battery explode from overcharging.
good info
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.
Your battery must be broken. To old.sulfated cell.or dried up cell
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...
@@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
what if I use a 12 volt wifi adapter? can it charge my battery?
Okay, I'm envisioning frying my cars electronics because I'm not qualified to do this. I'll wait until Monday morning and pay a guy to jump start me 😁Thanks for the video anyway.
If I don't have the right light bulb, can I use resistors in series?
Hi, yes you can, but you will need a lot of resistors to make 6W or even 12W in total.
Adaptör gücü kaç olmalı en az ?
60 A aküyü kaç saat şarj etmek gerekir bu şekilde ?
Hi can i use 12v led? I don't have a bulb
Good day, u mentioned the light bulb is to limit the ampere output from the power supply/laptop charger. If without the light bulb then it will kill the power supply just in case the battery is totally drained. U also mentioned can replace the light bulb with a 12V CPU fan. I have this CPU fan has a sticker stated 12V 0.18A (R). Does it means that 0.18A will be the ampere to charge the battery OR it is actually 3.82A output to the battery ? Which 3.82A = Max ampere output of the power supply/laptop charger (4A) deduct (-) CPU Fan ampere (0.18A) ? Thank you.
Good day!, It will be 0.18A, maybe even less... your 3.82A just is the maximum your power supply can provide. Imagine that you have 40A power supply, it will still charge your laptop fine, but you can also connect 10 laptops to it simultaneously without any problem, and one such power supply can charge them all at the same time.
Your 12V 0.18A means that the fan is designed to work with 12V and in such case the current will be 0.18A. The real question is "what voltage the fan will get?" in our case it will be 19V(PowerSupply) - 12V(Battery) = 7V (voltage at the fan). So the fan will get 7V instead of designed 12V, so the current probably be close to 0.18A, maybe less maybe, even more, it depends on the fan, the fan is not a resistor it is hard to predict what current will be, but it will be safe for the fan for sure. Just make sure you connected the fan correctly: plus of the fan should be connected to the plus of the power supply. I am happy that you are trying to understand :) This circuit looks simple but it is a bit tricky, it is not the best example for beginners.
@@ElectricalPro Since 0.18A (if using a fan as replacement for a 12V light bulb) will be the ampere going into the battery, does this also means that it will take longer time to charge the battery as compared to using a 12V light bulb ? Thank you for spending your time answering.
Yes, it will take a long time to charge the battery, especially if it is a big battery. You can also connect two fans in parallel to double the charging current. But with a proper lightbulb the charging current will be much higher and charging will be much faster. Usually, people in such cases limit current with a resistor, but in our case it will be a very powerful resistor, and it is not easy to find. For example, if the battery deeply discharged and has 10V then the difference in voltage 19V-10V=9V. Now let's say you want a 2A current... what resistor should you use? let's calculate: 9V/2A=4.5Ohms, but let's calculate how powerful the resistor should be 9V*2A=18W. Finding 18W resistor is not easy, but finding a 21W or 48W bulb is easy, that is why I used a light bulb. Also the voltage of the battery changes during charging, from 10V to 14.2V, which means the current will change as well.
Happy to help.
@@ElectricalPro Thank you for detailed explanation. I think I'll give up the idea of using a CPU fan to replace the light bulb. I thought a CPU fan uses less current (waste less energy) will make the remaining current from the power supply goes into the battery, but that is not the case.
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.
What happens if you connect normal 110v incandescent bulb instead?
With 110V light bulb, the charging process will be so slow that you will need to wait a couple of months to fully charge your battery.
amp=watts/volts
So
500w/110v = 4.5v amps
Or
50w12v = 4.1amps
Can this work? Or do I need to find 12v 21/50watts bulb
Thank you for your reply ^^
Better to find 12V 21/ 50 watts bulb. Here why:
You calculated working current of the bulb (4.5 amps) assuming that it will work with 110V, but in our case, it will work with 7 volts, not 110V, and therefore current will be much lower. (7V is the voltage drop between 19V and 12V).
Here is how I calculate:
First, let's calculate the resistance of the bulb:
110V/4.5A = 24.5 Ohms
Now let's calculate current of the bulb using 7V:
7V/24.5 Ohms = 0.286A
Conclusion: If you use 500W/110V bulb, charging current will be 0.286A, and it will take about one week to fully charge the battery (Assuming that battery capacity about 50Ah). But If you use 50W/12V charging current will be around 2.4A, and it will only take about 21 hours to fully charge the battery.
P.S I am not native English speaker, but I hope you understand me.
Electrical Projects thank you for taking the time to reply, really appreciate it ^^
thanks