I am trying to give power to my Arduino Board using a 12V 7.3 Ah Lead-Acid Battery but I am unable to do it.

I connected the battery to Arduino Uno (via DC Pin) and it worked for a couple of minutes but then, it automatically stopped working. I checked the voltage of the battery using a Multimeter from the same DC Pin which was connected with battery and board. The voltage was 12.62 volts. Then I thought my board might have been fried. So, I checked the board by connecting it with a 12V 2 Amp DC adapter and I found that my board was not fried and it was working fine with the Adaptor. The Adaptor was giving 12.48 volts voltage. Then, I again checked the board using battery but still it didn't work. I tried charging the battery via a charger but it still didn't work. I tried these steps multiple times but the results were always same.

I checked with my 12V DC Fan & some other devices also and it works perfectly, but it doesn't work with my Arduino Board. This indicates that my battery is in a good condition but not working with Arduino Board only. While Arduino is also in a good condition, working with 12V DC Adaptors but not with the Battery.

Please Help!

  • 1
    measure the voltage while the Arduino is connected
    – jsotola
    Commented Jul 27, 2019 at 17:25
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    your question is not about the Arduino ... your question is about how to determine if a battery is in good condition .... voting to close
    – jsotola
    Commented Jul 27, 2019 at 18:15
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    @jsotola I updated my question after further tests. Now please help. Commented Jul 28, 2019 at 5:54
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    a fan is not a voltmeter ... as i asked before, what is the battery voltage when the arduino is connected to the battery? ... also, what is the power adapter voltage when the arduino is connected to the power adapter?
    – jsotola
    Commented Jul 28, 2019 at 6:56
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    I have re-opened the question as it mentions Arduino 5 times and thus is hardly not about Arduinos.
    – Nick Gammon
    Commented Jul 28, 2019 at 7:05

1 Answer 1


The input voltage on the DC pin is specified as 7 to 12V. Your battery may well be supplying more than that, causing the voltage regulator to overheat and shut down.

The voltage was 12.62 volts.

That is out of spec for the Arduino Uno. When you operate out of specified voltages anything can happen, and that anything may not be very good.

You could get a buck converter to lower the voltage.

Certainly a Uno should be able to run for a long time on a 7 Ah battery (provided you are supplying voltages in range for it, preferably using a buck converter or similar to make sure that a fully-charged battery does not supply too high a voltage).

  • I was thinking the same - I had this exact problem about a year ago with a solar powered setup. Droped the input voltage to 10V and no problemo!
    – Bevan
    Commented Jul 28, 2019 at 8:55
  • Thank You So Much for your answer. I've read the Wikipedia article of the Buck Converter and I believe it will work in my case also, as you have already explained me. I have ordered a buck converter online. I'll update you as soon as it arrives and I use it in my project. Thanks Again. ❤️ Commented Jul 28, 2019 at 9:59
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    @Bevan Thanks for mentioning about your case. It strengthened my will to modify my current settings as told by Nick and not leave it. Otherwise I was thinking of changing the battery or the board 😅 Commented Jul 28, 2019 at 10:01
  • @Bevan One more help will be appreciated from your side. People have downvoted my post considering it as an off-topic post. It would be very great if you upvote it because it has resulted the decrease in my community reputation 😐. Commented Jul 28, 2019 at 10:04
  • @Nick Gammon sorry for the delayed update. My package with the buck converter just arrived today. I have installed it and it is working like butter. Thank You Commented Aug 4, 2019 at 20:38

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