I'm trying to power Arduino Nano with 7.4V LiPo battery and use it to run 2 DC motor using L293D. I have figured out how power it with the connection just like in the figure below(the diagram uses Uno and the battery is 9V but try to imagine it as Nano and 7.4V).figure I also found another way to power it by connecting the red wire from battery to Vin on the Arduino instead of connecting it to the positive power rail.

So, my question is which is a safer way to power it and what is the difference and risk of one the way I mention.

  • you ask if it is ok to connect the battery to Vin instead of the power rail of the breadboard from where it is connected to the Vin? there is no difference
    – Juraj
    Mar 8, 2018 at 16:12
  • What I mean is that, instead of having the red wire on the power rail, connect it directly to the Vin of the Arduino. Both of this works but my question is there any difference and which is safer to do? Mar 8, 2018 at 16:14
  • on the fritzing schema the battery is connected to 5V. it would damage the Atmega. the battery should be connected to Vin. And it makes no difference if direct, over the power rail or with T junction.
    – Juraj
    Mar 8, 2018 at 16:37

1 Answer 1


Connect it via the Vin pin. That way the 6-8.4 volt of the battery will go through the voltage regulator on the Nano, giving you a stable 5v.

What you show in your diagram is the wrong way of connecting the battery. The absolute maximum you can supply to the Arduino's 5V pin is 6 Volt. Atmel recommends no more than 5.5V. So your battery exceeds this when it's full.

  • sorry, where in the question you see Vcc pin mentioned?
    – Juraj
    Mar 8, 2018 at 16:23
  • I thought the Arduino pin was labeled Vcc, but it was 5V. Updated my question.
    – Gerben
    Mar 8, 2018 at 16:25
  • right. on the fritzing it is connected to 5 V. that is wrong
    – Juraj
    Mar 8, 2018 at 16:29
  • That is what I was trying to say.
    – Gerben
    Mar 8, 2018 at 16:35

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