I have a 5V arduino pro micro. I want to power it with a 3.7V lipo.

  • Should I use a step up module to convert it to 5V?

I also want to measure the voltage of the battery.

  • How can I do this?

Because I read that the power source also the reference voltage is so I cant measure it with an analog pin right?

I also use a lipo charging module to charge the battery.

Thanks for helping!


You can read the Arduino's supply voltage see here How to measure the supply voltage of Arduino without using an analog pin Alternatively use the internal 1.1V reference and a suitable voltage divider to read the lipo's voltage

  • 1
    I was just thinking if I use a step up module wouldn't the supply voltage be alwast 5V so I could use a analog pin without problems?
    – Robbe
    Dec 31 '19 at 16:18
  • Yes, if the output of said module is always 5V, best would be to use one of those charger boards with over-current and over-discharge protection. Or use a reference design.
    – Paul
    Dec 31 '19 at 17:42
  • Do you recommand a specific charger?
    – Robbe
    Jan 1 '20 at 15:07
  • Because I don't know any, I've never seen or used them.
    – Robbe
    Jan 1 '20 at 17:38

Yes, you should use a boost converter to convert the 3.7V from your battery to the 5V that the Arduino requires.

As I understand it, measuring voltage to determine charge level does not work well with lithium chemistry batteries since they hold a nearly constant voltage until they are almost completely depleted. Generally lithium batteries include a chip that measures current in and out and lets you query their charge level.

  • 1
    I don't think my battery has it. I bought this battery banggood.com/nl/… and this charging module banggood.com/nl/…. I was thinking to buy this converter banggood.com/…
    – Robbe
    Dec 31 '19 at 20:07
  • Yeah, you need a smart charging module then, as Paul says in a comment on the other answer.
    – Duncan C
    Dec 31 '19 at 20:32
  • What do you mean?
    – Robbe
    Dec 31 '19 at 20:47
  • I mean that you should not use a dumb charger to charge a lipo battery. You need an intelligent charge controller.
    – Duncan C
    Jan 1 '20 at 0:06
  • 1
    On this website the show the percentage of capacity in function of the voltage read from the lipo so it should be possible? google.com/amp/s/blog.ampow.com/lipo-voltage-chart
    – Robbe
    Jan 1 '20 at 12:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.