How to Run an Arduino for Years on a Battery

Summary

If you found this article after doing a search on Google, welcome! On this website you will find plenty of content around DIY home automation using open-source hardware. Enjoy the article!For most of the Arduino tutorials you will find on this website, power is usually not an issue as the Arduino is powered by the USB cable coming from the computer. However, sometimes you want to build systems that are going to be autonomous and powered by a battery.For example, you want to power a wireless motion detector just by using a set of batteries. The first idea would be to connect directly an Arduino board like the Arduino Uno R3 to a battery. Easy, right ? Well, it would work, but your battery would be depleted in a matter of days because some components like voltage regulators are always sucking power. So we need something better.The first thing we need is to build our own Arduino system with just the minimal set of components. The second part is to optimise the software so that the system only consumes power when it is actually doing something. And that’s exactly what we will see in this article.Hardware & Software RequirementsYou need several components to build you own Arduino system. The main piece of this project is of course the microcontroller that will run your Arduino sketches, like the ATMega328. You will need a chip with the Arduino bootloader. Buy your chip with it, it will make your life easier.In a previous project I used a FTDI breakout board to program the Arduino chip directly on the breadboard. But for this project I won’t have any external power running on the breadboard so I will just use an Arduino Uno board to program the microcontroller.To power the Arduino, you will need a battery. The best is to power the Arduino directly from the battery, so you don’t have to use any voltage regulators that will suck some power. I used a set of two AA batteries (1.5V each) with a battery holder thus powering the microcontroller with around 3V, which is fine acco...