instructables

How to Make a 12v Battery Charger

by Steve Willson Kujur

Hey! everyone My name is Steve .

Today i'm going to show you How to Make 12vBattery Charge

With this charge you can charge any type of 12 vbattery even your car battery

it is very necessary in cold days because batterydrains out very quickly .

This Charger features 2 step Charging 1. ConstantCurrent 2. Constant Voltage

it is very safe and stable for daily use "it's verystandard "

Click Here to See The VideoClick here to see the new video

Let's Start

How to Make a 12v Battery Charger: Page 1

Step 1: Stuff I Used

Dc to Dc Step Down Converter - clickAlligator Clip - clickMulti-meter - clickLaptop charger

Dc to Dc Step Down Converter

it's will convert 19 volts from your charger to 14 volts to charge the batteryit'll provide constant voltage and constant current. ( very necessary )it comes with 3 indicators led (red, blue and green) red show constant current blue show load andgreen show constant voltage "full charge"

Features

Input voltage range:6-38 VDC (Note: input voltage not exceeding 38V)Output voltage range:1.25-36VDC adjustableOutput current: 0-5AOutput power: 75WHigh efficiency up to 96%Built in thermal shutdown functionBuilt in current limit functionBuilt in output short protection function

Step 2: Prepare the Adapter

Follow the Steps

1. Cut down the jack of the adapter2. Remove the outer shield with a blade (Carefully)3. you'll see 2 wire red and black , black is negative and red is positive (see the image)

How to Make a 12v Battery Charger: Page 2

Step 3: Connection

You can see the label over the board

The red wire of adapter will go to "IN+" positive of the board (see the image)The black wire of adapter will go to "IN-" negative of the boardtight the screw terminal with a screw driver

Now connect alligator clip

Red alligator clip wire will go to "OUT+" Positive of the Board (see the image)Black alligator clip wire will go to "OUT-" Negative of the Board

How to Make a 12v Battery Charger: Page 3

Step 4: Configuration

Now you need a multi-meter to set it up

Plug the power to the adapterConnect the black alligator clip to negative lead of multi-meter and red alligator clip to positive leadyou can see 2 Potentiometer over the board (see the image)first one is voltage and second one is currentNow select the DC voltage reading on your multi-meter and turn the Potentiometer with a screwdriver until you get 14 volts reading on multi-meterNow select the Current Reading on your multi-meter and turn the second Potentiometer with ascrew driver until you get 2 amps reading on multi-meter (you can go up to 5 amps all it dependupon the battery capacity if you have a bigger battery "like a car battery you can go up to 5 amps "

How to Make a 12v Battery Charger: Page 4

Most batteries require an unstable (cyclic) charging rate or the battery will develop Dendritic growthand self discharge. How does your charger avoid this issue?

You are correct lead-acid cells have to have a cyclic charge and not a steady charge...once lead-acid batteries are charged without the benefit of cyclic charging..over time they will self discharge/not hold a charge at all.

Step 5: You Are Good to Go

Just plug the red alligator clip to positive of the batteryand black alligator clip to negative of the battery

and plug the power to the adapter

You'll see blue led will glow there it means it ischarging If you see green led glows after some time itmeans the battery is fully charged

If You see Red led with Blue led that means it is inconstant current charging

Click Here to See The VideoEnjoyThank you for visiting my Instructables

Stay tuned for next Projects

How to Make a 12v Battery Charger: Page 5

Bro i need charger for 6v battery

I'm surprised @instructables let this fly for so long...

Excellent bro

I must make one , thank you for sharing .

You can use a 12V light bulb if you don't have a DC to DC converter.

This is a big mistake, NOBODY CONNECT THE AMMETER ON THE EXIT AS IT SAYS ON THEVIDEO ... IT WILL BURST !!!

Connecting the Amperimeter to the output will burst the XL4015E1 IC or Multimeter.

It seems to me another video to sell the regulating boards, these boards only regulate the Volts, ifplacing the meter in series with the battery only gives a maximum of 400mA, even with anIndustrial Well of 12.5A Mean Well 12VDC.

Turning the potentiometer knob W 102 does nothing ...

It sucks this board.

Nice!

Request your advice - I keep a spare 12 volt SLA battery in my car. Been looking for a way tocharge it in the car. Do you see any issues with an approach that would use a boost converter offthe 14.4 alternator voltage as power supply for the step down converter for charging? It seemscleaner than inverting the car power to 110 volts AC to provide power to a lap top charger. Is theresomething I am missing?

I made it.

Warning! Be sure to connect your power source to the board BEFORE you connect the battery! Ifnot it will release the "magic smoke" inside :) and will not work anymore!

Hey just a heads up your charging sealed lead acid batteries with a lithium charger that cost 1.96cents. Now arguably there are chargers that can recognize between battery chemistries but eventhe cadex I use to analyze balance and charge multi cell banks cannot and must be programmeddifferently for each and I mean it's overkill as far as charges go.

In basic terms each chemistry of rechargeable battery has a unique charge and discharge cycle.

lithiums being the happiest out of nickel metal hydride / nickel cadmium and sealed lead acid as faras being fully depleted and then recharged makes them better for items which will die fully betweencharges as well as for items that must be recharged from many different states of charge. Be thathalf dead or dead for a week.

Without getting into the theory too much the gist of what I'm bringing up is sealed lead acids maynot necessarily be charged most effectively with a lithium battery charge curve.... nor is itnecessarily the safest way to do so, same as how a lithium drill pack can't be charged safely on acheap nickel metal charger, because the charge curves are wrong for the different chemistries....

there are specific chargers for specific chemistries and I'm afraid that the 1.98 charger advertisedfor lithium may not be the best choice for your application. Do not put it in your car please.

In this case hopping chemistries while adding a multi stage charger isn't actually adding much as

//www.youtube.com/embed/JfWXKw0JvJ0

How to Make a 12v Battery Charger: Page 6

far as safety measures go. Sealed leads would prefer constant voltage than ramped voltage,utilizing constant amperage up until a full charge would be a better move, then at full charge all thatneeds to happen is a switch from full to float or trickle charge. if I'm remembering properly. See alithium pack charger increases voltage incrementally, not necessarily the best for a SLA.

Take a peek online looking up different charge curves and I bet you'll catch what I mean real quick.Still for all intents an purposes good one for making something to fix your problems, right on. Justthought you could use the advice if you were wondering what the deal was with that SLA now thathe's been on that charger.

Take note using your multi meter the next time you choose to you use your set up, read the batterybefore applying charge and then watch how the charger attempts to charge the battery. SLA wouldreally benefit from a higher voltage than what is desired being the original charge voltage. Forexample 14.4 volts from an alternator to your car battery. When the battery is low, I bet the chargerwill recognize the voltage and begin by applying a lower voltage than the battery is rated for. Thisand this alone is enough to damage the cells, that's why I came to tell you. Anyway best of luck toyou

Your comments are well taken, however, it's not clear they apply here. If you look up the chip andboard the OP is using you'll learn more. The part about 'lithium charger' appears to only be"marketing". Technically speaking, the little board isn't actually a 'charger' per se. It simply could beused to MAKE one of those. But I expect the seller gets more hits when that appears in the title!Other vendors of the same part leave out those marketing buzzwords.

This is the component on the board which is just a regulator, not a charge controller:

http://i-makers.info/resource/XL4015%20datasheet.p...

So it appears to be a voltage and current regulator, i.e. it applies the configured voltage up to amaximum of the configured current. So from a charging standpoint, I believe it works as a currentlimited (not controlled) constant voltage charger. As I have not found the full board schematic, thisis a still an educated guess - but the chip itself is sold as a regulator NOT as an intelligent chargerchip.

You are right to be concerned about properly matching battery chemistry to charging approach.Many thanks!

I've done some more digging and found some videos of people playing with this board. One ofitems lists the additional parts on the board - an op-amp and an LM317 regulator. But still noschematic.

I bought a couple of these and found that when connected to a gel-cel (SLA) and set for anappropriate max current, it kept the voltage constant but the current draw went down as the batterycharged.

I have several of these little PSU's, they are general purpose step down PSUs (some provide stepup/down). At the current supplied, charge curves will make little difference. SLA used to be used inolder motorcycles with the crudest of chargers.

I use the bigger PSU of this type to supply a steady current to my Li-Po charger ;)

The voltage should be set to 13.8 V (not 14V) for lead acid charging. I'd also set the current quitelow as the charger may not cope at higher currents. As the voltage reaches the set voltage, socharging will of course diminish. It's not ideal but is probably more accurate than may mains carbattery chargers and at least as good, if not better as those used in burglar (12V) and fire (24V)alarms. In an emergency, for a few pennies, who really cares? In the past I've charged Ni-Cds viaa length of co-ax cable with a car battery charger ;)

How to Make a 12v Battery Charger: Page 7

In addition, this unit will charge a "flat" battery, whereas many of the "electronic" car batterychargers will refuse to supply a charge if the battery voltage is "too low". So useful to get somecharge into the battery.

I have to agree elsewhere, it's more of a "how to assemble" rather than "make", little more thanstripping wires is shown - however still useful to those that don't know.

If you want to know how to charge SLA batteries correctly download the panasonic manual andread it carefully and you will notice that most chargers don't work optimal.

https://eu.industrial.panasonic.com/sites/default/...

P.S. I would be happy to find a manual for charging LiFePo4 as good as this one.

Great feedback! This was something I was concerned about.

Not auch good idea to adjust With connected battery. voltage Setup without. then put a bulb 1255w and adjust amp's. charging current should be bat capacy /10 now disconnect bulb andconnect battery.

Nice to know about this $2 DC/DC. I would think that one would want to float PbA around 13.6 to13.8v. If your power supply has a 5v line, I wonder if we could/should set up a handfull of USBplugs for phone charging too.

Sorry, but it's not "how to make", It's"how to buy". No offence

Definitely how to buy. Maybe "how to use", if you insist...

it's depend upon views . how you see it

Thanks, I have everything but the converter. $2 backup charger is pretty neat.

welcome

Looks like you clipped the cable awfully close to the connector. A helpful tip is to leave about a 6inch tail so it can be reused at some point in time.

yeah you are right. in my case I don't need this anymore so i did.

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