How to power an Arduino with a battery

Perhaps you’ve been powering your Arduino projects from the computer through the USB cable all this time and you feel it’s time to finally let your Arduino free of its tether. Perhaps you would like to know how to power your Arduino from a battery. No despair! It’s really easy and I’ll show you in detail.

Arduino power requirements

The Arduino has no problem running off any supply of electricity, as long as the power requirements are met.

Generally, it is recommended that the Arduino be powered with a 7-12V DC supply. Too low and the board might not work correctly since the regulated 5V supply might end up too low. Too high and the board might get damaged by the voltage regulator overheating. This means a 9V battery sits nicely in between these limits and is ideal for powering the Arduino board.

Power pin headers

So how to connect a 9V battery to the Arduino board? Well, there are two ways to go about it. One way is to connect your battery to the GND and Vin connections on the power header of the Arduino. This will let the power through the regulator to get your 5V and 3.3V supplies.

Arduino Power Header with the power wires connected to Vin and GND
Powering the Arduino on the Vin and GND pin headers
A battery clip will allow you to easily make the connection between the battery and Arduino.
A battery clip will allow you to easily make the connection between the battery and Arduino.

Power jack

The other method is to make use of the supplied power socket at the edge of the board.
Arduino power jack and a power plug
You will need:

  • 2.1mm power plug
  • soldering iron and solder

You need to solder the wires from the 9V battery clip to the plug such that the black ground wire is connected to the outside of the plug and the red wire to the inside of the plug.
2.1mm plug with red wire soldered to center pin

External powersupply

If you wish, you could also power the Arduino from a standalone power supply such as a wall brick or lab supply. Make sure the voltage and polarity of the plug are correct by measuring with a multimeter! We definitely don’t want to permanently damage the Arduino board.

MW2122A Power Supply set to 7.5V
Check the voltage on adjustable power supplies before connecting it to the Arduino

Solar power

If your Arduino project is installed outside where there is sunlight, it might be a fun idea to power it with solar power. Generally, one would power the Arduino from a rechargeable battery. Perhaps a lithium polymer battery? The solar panel should be connected to charge the battery using a special solar power regulator and LiPo charger circuit. The regulator makes sure that there is no over- or under-charging to prevent damage to the battery and your Arduino.
If interested, here is one option of powering your Arduino projects using solar power.

Please leave a comment if you found this helpful or have any questions or issues with this post.


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