I would like to power my arduino nano with a 9V battery, but I would also like to measure the voltage of the battery to know its charge level.
Can I use the MAX471 Voltage Current Sensor module by connecting the VIN pin to my battery and VOUT to my arduino ?

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    what kind of a 9 V battery?
    – jsotola
    Jun 3, 2021 at 2:26
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    If you only need to measure voltage, why not use an Arduino A/D input? All you need to do is connect a voltage divide across the 9V terminals to divide down to the A/D range. Use big resistors in the 100K to 1Meg range for low drain.
    – Boggyman
    Jun 3, 2021 at 12:23
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    @Boggyman: If there are other analogRead channels active, 100k to 1M might be a bit high to load the ADC in time. An additional capacitor in parallel to the voltage divider low side might help... Jun 3, 2021 at 14:52
  • @jsotola This is a 9V GF22
    – NOMAD
    Jun 4, 2021 at 16:32

1 Answer 1


If you want measuring a "battery level" in mAh for example, you must measure Voltage AND Current, so INA219 is a better deal (it is a I2C control).

  • Are you sure that this would allow me to power my Arduino, if so is there a difference in autonomy with this module rather than the assembly of @Boggyman (less wasting) ?
    – NOMAD
    Jun 17, 2021 at 12:18

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