Using DIfferent Power Sources Provides Inconsistent Results

Using Arduino General Electronics
1

Hi guys,

I have an Arduino project that:

Runs perfectly off the connected USB cable

  • I do not know the given voltage or current

Runs perfectly with a Molicel P42A 21700

  • This is connected to the Vin and GND ports on the Arduino
  • The P42A has a 45A discharge current
    • The P42A has a cell voltage of:
    • Nominal 3.6 V
    • Charge 4.2 V
    • Discharge 2.5 V
  • When I plug this into the barrel jack, the arduino does not work

Does not run properly at all off an Energizer 9V battery

  • This is connected to the barrel plug of the Arduino
  • When I plug it straight into the Vin/GND on the board it still doesn't work properly

Connected to the Arduino I have:

  • 2 MAX7219 Led Controllers with an 8x8 LED Matrix attached
    • These 2 LED Controllers and Arrays are connected in Series
    • They run power off of the 5V and GND of the Arduino
  • 1 HC-06 Bluetooth Module
    • This runs off of the 3.3V and other GND of the Arduino

I have included a schematic/diagram of my project in it's working form.
Unfortunately the forum will not let me upload the picture.

What would be the best way to make it so that my project will work with either a single 21700 or two 18650s? The barrel jack does not seem to like any power source for the scope of my project.

Also if using the Li-Ion cells, do these pose any safety risk of discharging it too much?

Thank you!

2

Hi

Have a look at the sticky on how to get the best out of this forum , meanwhile :

  • Usb is 5v
  • the small PP3 type batteries do not have enough capacity to run anything significant
    -You need at least 7v volts on Vin for it to work.
  • you cannot power significant loads directly off the Arduino without damaging it .
  • Have a look ( google ) at how to draw a schematic.
3

Hi there,

The actual Vin pin on the arduino works with my 3.6V 21700 battery. Which doesn't make sense to me since the Vin can't accept less than 7V

I did include a schematic of the working version with the single 21700 battery. It it hyperlinked in my post since I get an error uploading every time I try to.

[Album] imgur.com
4

Actually, it can, but there is a significant voltage drop, and it is not guaranteed that the Arduino will work on that voltage.

Follow the rules about Vin (apply 7V or greater) and you won't be confused.

Use a step up converter like this one to generate 5V from your battery, and apply that to the 5V pin.

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5

Schematic

Arduino specification

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