12v Automatic Charger (Auto Cut OFF)

what is auto cut off battery charger?

some off charger maybe can't stop charging when the battery is fully charged.

Step 1: Circuit

so we want to show you a simple circuit for the charger when the battery is fully charged, the charging automatically stopping,

this is a circuit of the auto cut off battery charger, it has only:-

- one NPN transistor such as c1815 for controlling the charging,

- relay for cutting off this current path through the battery after fully charged,

- 10 kilo-ohm variable resistor connected to the base of the transistor,

the variable resistor used for restricting the voltage from how many volts you want to stop charging!

Step 2: Print

We prepared this circuit for you,

you can download it from the link below

12v Automatic Charger (Auto Cut OFF)

then print it by any printer,

and use any prototyping electronic circuit after that stick the paper to the board,

Step 3: Video

you can see this video and make step by step with this video

Comments

[amarakuruppu]

Dear sir, I had a problem with this circuit, There is a trouble with fix LED Bulbs green and red .I think the polarity on circuit is change.

[ikeogu daniell]

Is your circuit working

[amarakuruppu]

Unable to control the charging voltage through 10k VR.no changers how it make correctly.

[sharma420p]

I made this but it's not working well... without battery it's just fine but when i attach battery it's always shows battery fully charged....no matter how much empty the battery is...plz help

[colin55]

There are so many mistakes with this circuit.
See the correct circuit on my website:
http://www.talkingelectronics.com/projects/200TrCc...

Colin Mitchell
TALKING ELECTRONICS.com

[JureT]

Thank you Mr.Mitchell on your advise which helped a lot

[RishanR]

There are mistakes on your diagrams too. Cannot charge 12V battery from 12Vdc.

[colin55]

If you read my article you will find this comment:
Most 12v Plug Packs produce 15v to 16v on NO-LOAD and we are
using this feature to charge the battery.

[terezkaterka]

Colin 55 a LED na indikáciu sú kde v Tvojej, akože dobrej schéme?

[RishanR]

Hi I'm Rishan . Isn't these LEDs connected reverse ? and It's monitoring Charger Voltage not the Battery Voltage.

[Hanzalaibnzahid]

can i use a tip122 instead of the relay????

[85sinoda]

I created this circuit successfully...and it works well...one thing I notice is that when the battery is about to be fully charge...the relay is tripping and only stop until it fully activate the full charge led...how to stop the tripping sir..i want it to just like it will click just once as it activates...thanks sir...

[Emerald 1234]

Put a capacitor to the collector of the transistor...I think it should work well that way

[Sujeevan1]

Hi,im sujeeva from srilanka.i want to know what is the maximum input voltage for this circuit.thank you.

[AdityaK201]

All Resistance kitane Watt ka hai plz comment

[ShreyashH1]

This circuit contains major fault! Most batteries require intiatial charge current less than .39 Amps this feature is missing and hence may damage battery.

[terezkaterka]

LED diody sú zapojené opačne, ale inak je prístroj dobrý a trimrom mi idú nastaviť napätia asi 13,8 V - 15 V pri ktorom vypne a napätie pri ktorom zapne asi 10,9 V Požiadajte o informácie, ktoré treba zmeniť, aby bolo funkčné pre 6 V akumulátor. Ďakujem za odpoveď.

[asifu3]

Buddy its working good but , Important Question ??? why you are not showing when you are reducing voltage <14.4v . The relay should reactivate when voltages goes <14.4 but its no reactive .

[altanemre]

I wonder if battery reduce a value it starts automatically charging?

[Hamelc]

I made this twice and it didn't work. Has anyone made it and had it work hooked up to a charger?