Feeding Power To Arduino


When you are working with your Arduino, you usually feed it through the USB cable that goes to the computer. However, once you finish programming it, either you resign to leave it connected all day to your PC (without being able to turn it off) or you are looking for another way to power the Arduino.

Probably the most common way to power an Arduino (without using your computer) is through a 9V battery. Partly because they are the most common connectors to power an Arduino that can be found in the market, which makes it simple, easy and working option, but the battery is gradually discharging.


Overheating voltage

When we talk about overheating voltage, I mean all the volts that your Arduino spends, but it does not use. Most of the Arduinos work at 5V, others like the DUE board do it at 3.3V. Whatever your model, they all have a voltage regulator, basically it is a component that converts the voltage with which you feed the board, the recommended is to feed between 7 to 12V to5V or 3.3V, the remaining voltage heats up your Arduino board. For example, feeding power to an Arduino with more than 20V would destroy it.

This regulator needs a minimum voltage to provide 5V that is around 6.5-7V but everything that is above that value is wasted.


Now, the mAh or milliampere is the term used to determine the duration of a battery. If your battery has 1000mAh, you can feed something that consumes 1000mA for one hour (or 100mA for 10 hours).

Actually, this is only true in theory, in practice, the faster your battery is discharged, the more power it will be dissipating in the internal resistance it has. That means that if it really lasted 10 hours feeding a device that consumes 100mA, probably would not last an hour feeding something with a consumption of 1000mA.

To give you an idea of the consumption of your project, a small circuit with an Arduino board and a display already suppose a consumption above 150mAh, while a rechargeable battery of 9V has around 300mAh. For this reason, feeding power to an Arduino with a 9V battery is a bad option.



It is basically the cell phone charge adapter. If you want to power an Arduino permanently and do not need your project to move, you can connect it to the supply of the contacts on your home wall and forget to by batteries.

2. AA Batteries

Typical batteries provide 1.5V. You can put several in series until you reach the voltage you need (the ideal is to put 6) and feed power the Arduino with them.

The difference between using these batteries and using the 9V batteries is huge. A single AA alkaline battery has between 2700-2900 mAh (for the 300mAh of a rechargeable 9V), so they are a very good choice. The only drawback with this option is that as batteries are spent, you will have to buy batteries often. Even so, a highly recommended option.


This option consists of power the Arduino board with a cell phone battery. LiPo batteries are very fashionable thanks to their duration (they have many mAh). Think that if it is the option that large companies choose to manufacture their smartphones and tablets and others, it will be something. They have a quite long lifespan, which makes it worthwhile to use this resource even if they are a little more expensive than AA batteries.

Without a doubt, they are the best option to power your car to radio control, drone or any mobile device that you can think of.

There are LiPo batteries of different voltages and capacities. In the case of feeding power to an Arduino, the best option is to use a 7.4V battery and at least 1600mAh.

We recommend you buy Hobbyking batteries