How Long Can An Arduino Run On Batteries? I Tested 6 Of The Most Common Boards

today we're going to be looking at the power consumption of a number of different arduino boards with the aim being to try and power them for as long as possible using two 18650 lithium-ion batteries these batteries are 3.7 volts each and come in a range of capacities from eighteen hundred to forty five hundred milliamp hours these ones are on the higher end at forty two hundred million powers meaning that they can supply four point two milliamps for a thousand hours or four hundred and twenty milliamps for ten hours or any combination of currents and time for which the product is 4200 we're going to be testing the power consumption of six different arduino boards i've got an arduino mega an uno a nano a pro micro and then a 5 volt pro mini and a 3.3 volt pro menu most arduino boards require a minimum input voltage of around 6 volts so we'll be using 2 batteries with an input voltage of 7.4 volts to power these boards i've also included a 3.3 volt board which is able to run on a single battery i'm going to be loading a basic sketch onto each arduino which has an 8 second delay and then flashes the onboard led for 100 milliseconds just to tell us that the sketch is running this will then just loop repeatedly the atmega chips on these boards support a number of different sleep modes which turns off any unused peripherals in order to conserve power i'm not going to go into too much detail on how these work but we'll be using a library which enables you to put the arduino to sleep for a certain amount of time once all that interrupt is triggered so for these boards i'll include two tests one without the sleep mode and one in which the arduino is put to sleep for the eight seconds between flashes instead of running the delay i'll discuss this option a bit later when you look at the difference in power consumption let's get started with setting up the test rig i've connected the two batteries in series and then connected them to my multimeter to measure the current draw the multimeter is going to be showing the current drawn in milliamps we'll start off with arduino uno since it's one of the most common boards available this board is designed to be more robust and easy to use than power efficient or compact so our data is going to do very well in the power test but let's try it out as a starting point [Music] in each test i'll allow the current to stabilize for a bit and then record the average current drawn during the delay time we'll ignore the peak current drawn while the led is flashed as this is only on for 100 milliseconds every eight seconds which is only around one percent of the on time on the you know in normal mode we get a current draw of 54.4 milliamps which means it would run for around 77 hours or three days on the two 18650 batteries now let's load the sleep sketch and see if there's any difference the current increase when the led flashes is now more noticeable so if we use the sleep mode between flashes the current consumption goes down to 38.2 milliamps so expect it to be able to run for around 110 hours or 5 days now let's try an arduino mega [Music] as expected the mega draws a bit more power than the uno it draws around 77.7 milliamps so it would only last for around 54 hours or two days now let's try low power mode [Music] so in low power mode an arduino mega draws around 31.7 milliamps and would run for around 132 hours or 6 days next we have an arduino nano as you can see the nano seems to be a lot more power efficient than the uno or the mega the nano draws around 25.5 milliamps so it expects it to run for 165 hours or 7 days so we've managed to get a week of battery life now let's try the nano in low power mode using the sleep mode sketch the nano draws only 6.4 milliamps so it would run for around 656 hours or 27 days so we're almost at a month let's see if the pro micro can get us there [Music] the pro micro actually did a lot worse than the nano they drew around 43.4 milliamps so it would only last for 97 hours or 4 days let's see if low power mode makes any difference [Music] in low power mode the pro micro drew 9.25 milliamps so it's much better than the mega and the uno but the nano is still the most efficient next we're going to try powering a pro mini this is a very similar form factor to the pro macro but it has a different chip and the onboard usb host has been removed so you'll need an external programmer to connect it to your computer the pro mini uses just 19.1 milliamps which is a little less than the nano and means that you'll get around 220 hours or 9 days now let's try the pro mini in low power mode [Music] if we put the pro mini to sleep between flashes it uses just 3.2 milliamps which means that it'll run for around 1 313 hours or 55 days so we're now getting closer to 2 months lastly let's try the 3.3 volt arduino pro mini and see if it does better than the 5 volt version [Music] the 3.3 volt pro mini draws substantially less current than the 5 volt version just 5.5 milliamps which is even better than the nano in low power mode so we've seen that it'll run for a month in normal mode let's see how long it'll run in low power mode the 3.3 volt pro mini uses just 1.6 milliamps in low power mode so it'll run for around 109 days which is a bit over three months let's see if that changes if we power it with just one battery remember that if we're halving the input voltage we'd expect the current to increase to supply the same amount of power to the arduino strangely there was actually a slight decrease in the input current so you'll actually get better battery life by powering a 3.3 volt pro mini on a single 18650 battery you'll get almost four months so if we look at our full set of results the most power efficient board in both modes is the 3.3 volt pro mini lasting almost 4 months on a single 18650 battery there's also a significant decrease in power consumption when using sleep mode so you should definitely consider using it if you're designing a battery based project i obviously can't have the arduino sleeping the whole time it's actually expected to do something if it's connected up to a project but on most projects where you'd be looking to power the arduino using batteries you're only using the arduino for a fraction of the time that the system is powered up for example if we look at a soil moisture monitor soil doesn't suddenly dry up in a couple of milliseconds and even watering the plant takes a minute or two for the water to be evenly soaked up in all of the soil and your plant isn't gonna die if it's roots or dry for two seconds so you realistically only need to take soil moisture readings in minutes intervals rather than every couple of hundred milliseconds so you could have your arduino sleep for a minute and then take the measurements and then go back to sleep again the measurements also only take a couple of hundred milliseconds to execute so your arduino would be sleeping for most of its on time similarly for weather stations even rapid outdoor temperature changes only change over a number of minutes so you can set your arduino to wake up every five minutes and take a new temperature and humidity measurement rather than take measurements on every loop cycle it's also important to note that there's a difference between putting the arduino to sleep and simply putting delays into your code delays don't stop the arduino from processing operations so they just told the arduino not to proceed until a certain amount of time is passed you can think of the two like this putting a delay into your code is like having a child ask are we there yet are we there yet are we there yet over and over again until the answer is yes and it's able to proceed putting arduino to sleep is like setting an alarm and allowing the arduino to do nothing until the alarm rings when it wakes up again look out for the next video in which i'm going to try and further reduce the power consumption of a 3.3 volt arduino pro mini and see if we can get it to run for over a year on a single 18650 battery [Music] thanks for watching please remember to like this video if you enjoyed it and subscribe for more tech and electronics projects tutorials and reviews [Music]

Channel: Michael Klements

Views: 28,531

Rating: 4.9086757 out of 5

Keywords: Arduino, Arduino Power Consumption, Arduino Current Draw, Power, Current, Energy, Save Power, Low Power Mode, Sleep Mode, Uno, Mega, Nano, Pro Micro, Pro Mini, 5V Pro Mini, 3.3V Pro Mini, Lithium Ion Battery, Lithium Battery, 18650 Battery, 18650

Id: 5cYN5-Spnos

Length: 10min 10sec (610 seconds)

Published: Mon Aug 17 2020