Externally Powering up Arduino

Hello Everyone,

I am working on Arduino UNO R3 in my project.
I have to make a standalone system,so I was powering up the Arduino externally with 9V DC Battery,connected on Pin-Vin of Arduino, and then connecting the Pin-5V with the remaining circuitry of LEDs,LCD,etc.
The LED stating ON condition on the Arduino was lit,so I thought the board is powered and the remaining circuitry will work fine,but it didn't work properly.

So suggest me proper steps to externally power the UNO Board.

The 9Vdc "battery", was it a smoke detector size.
If so, they are not designed to do the work with the load, form arduino and all your LEDs.

You will need a supply that can provide more current.
Have you measured how much current is being drawn from the battery?

Tom... :slight_smile:

Hi hrishi,

Do you have a "wall wart" power supply? Alternatively, just power the Arduino from the USB to see if this is a power problem.

Also - try to just run the Arduino with an attached LED. That should work just fine since a single LED doesn't draw much power. If it still doesn't work -- then the power supply probably isn't the problem.

As TomGeorge says, 9V batteries can be pretty wimpy, depending on what you are trying to power with them.


@ TomGeorge & @ patduino :

Thank you Sir for your help,I just saw your feedbacks on this topic and I had figured out the exact same things.

I had to make my system standalone,as those typical 9V Batteries couldn't provide enough current (I needed 300mA as per my load),so I used 2 batteries providing 4V-1A current and connected them in series.

It worked fine and for exact 3 hrs the system remains ON.