I am new to arduino. It is costly for me to buy an arduino uno board. Therefore I am going to make a Arduino with breadboard at my home. I also want to make my Arduino portable. Arduino Uno boards can be powered up with battery. But can I do so with my homemade Arduino? If it is possible, what things need to be included in my homemade Arduino?

  • 1
    A modern irony is that it can by hard to buy a single processor for less than the cost of a clone board - especially if you want one with the bootloader pre-programmed. And while the USB-serial chips used on some of the clones can be problematic (as much with the Windows drivers as the hardware), you will need to supply similar functionality when breadboarding, which tends to cost as much as or more than MCU itself. May 23, 2016 at 18:35
  • A breadboard and all components needed will often actually cost more as one of the boards from e-bay. It should also be very easy to find millions of tutorials on how to make your own Arduino. For the battery part you will need some kind of regulator. And to be honest, this is also one of the basic "electronic engineering" projects of which millions of articles and blogs can be found. Circuitry and everything can be found most regulators' datasheet.
    – aaa
    May 25, 2016 at 13:44
  • 1
    But can I do so with my homemade arduino? - of course. Why on earth wouldn't you?
    – Nick Gammon
    May 28, 2016 at 9:13

5 Answers 5


First, of course, you'll need a battery with enough capacity, and voltage enough greater than 5v (assuming you want to run your home-built at 5v - typical, but you could run it lower, say 3.3v) to give enough run-time before the battery discharges to where it can no longer supply the system. Note that the 9v, so-called "Transistor battery" is not capable of supplying much current. A battery pack of off-the-shelf alkaline batteries or rechargables, or a Lithium Polymer rechargable battery will do much better.

You'll need a low dropout voltage regulator to reduce the battery voltage to your chosen Arduino supply voltage. National Semiconductor's LM1117 would be a good choice. The diagram below from NS's datasheet shows a simple-to-make voltage regulator. Its input is your battery; its output will be the supply voltage to the chip and any accessory circuitry.

Typical fixed voltage circuit

  • Linear regulators mean wasted battery capacity. Unless something in the system needs a consistent voltage, one may not be needed. May 23, 2016 at 18:40
  • That never occurred to me but of course! The programmer, FTDI cable in my case, would have to guarantee clean power during programming (or one could regulate its output). But once built & programmed, it could run off of 4.5v from 3 Alkalines until it fails or until it detects the voltage is too low for the clock frequency. Thanks for the idea!
    – JRobert
    May 28, 2016 at 20:04

Yes you can power it from a battery, as long as you add a 5V regulator to your board. You might get strange behaviour when the battery is running low.

These links all tell you what you need to build the board, good luck.




  • 1
    You won't get strange behavior if brownout detecting is enabled (which it is by default in Arduino's).
    – Gerben
    May 23, 2016 at 14:05

I mostly use two AA batteries to power my 'standalone' ATMega328s. One of the downsides of this, is that you can't run the ATMega at 16Mhz, but only at 8Mhz. I don't mind that, as running at a slower speed reduces the current usage.

You could use 3 AA batteries, or 4 rechargeable AA batteries, instead to get a voltage that is closer to 5V

To get your circuit to run for more than a couple of days, you have to implement ways of reducing the current consumption. One of the first things would be to put the processor into sleep mode.

  • 1
    Indeed, one of the few remaining advantages of the ATmega processor is it's relatively wide voltage range. As long as you don't exceed the maximum when alkaline cells are new, or drop below the minimum for the chosen clock when NiMH or NiCd are nearing time for recharge, running directly off of them is a possibility with this processor not shared to the same degree by many newer alternatives. May 23, 2016 at 18:33

You can use 9 Volt batteries to power most Arduino Boards. For instance the Mega 2560 has a rated Vin range of 7 to 12 Volts. A car battery can be used for longer life, although not nearly as portable as a 9 Volt one with a clip. I'd recommend a common 7809 Positive Voltage Regulator TO-220 between a car battery charged using a car alternator and an Arduino board though, because the Voltage may vary quite a bit above the 12 V maximum.

I've used batteries with microprocessors for years for various embedded applications where access to AC is inconvenient, impractical, or nearly impossible.

The Mega page on the Arduino site explicitly permits battery power 1.

Helpful Guidelines

Here are some important criteria to meet.

  • The Voltage is within the published range for the Arduino model you are using
  • The positive of the battery supply connected to Vin (NOT any of the other power pins)
  • The negative of the battery supply is connected to Gnd
  • Critical applications don't run under the assumption that the battery will never drop below the minimum of the published supply range
  • The header is never plugged in backwards or in the wrong location, which would likely damage the Arduino circuitry

Connection Safety Using Plug and Jack

If you are connecting and disconnecting the Arduino from your battery frequently or you just want .

See the Power section of the pageto make sure you never plug in the header wrong, you can connect your battery supply to the Arduino board's existing power jack 2. When connecting a battery supply to an Arduino compatible plug, you can ensure that the plug's inner conductor is positive in Voltage relative to the outer sheath using a Voltmeter.

Battery Use in Robotics and Flight Control

A 9V battery will eventually drop in Voltage below the rated minimum, upon which the operation of the board may fail at any time, so you may want to add more 9V batteries in parallel to extend your battery supply's life 3.

Another approach common in robotics or flight control applications, to preemptively avoid erratic behavior as the battery drains below operational thresholds, is to use the low voltage detection features of the CPU. The Atmel CPU used by the Arduino Mega 2560 4 has a Brown-Out Detection feature 5.

A simpler approach for critical applications is a resistor divider on an analog input is another related approach.


[1] See the Power section of this page https://www.arduino.cc/en/Main/ArduinoBoardMega

[2] Information about compatible plugs is at http://forum.arduino.cc/index.php?topic=4892.0.

[3] Batteries may vary in Voltage when purchased, but some small variance above or below 9V hurts neither the batteries nor the Arduino. They will equalize themselves without dissipating (wasting) much energy, so you will get close to N times the battery life, where N is the number of 9V batteries in parallel (See https://electronics.stackexchange.com/questions/177204/will-connecting-two-batteries-in-parallel-increase-current-drawn-in-simple-led-c and http://www.zbattery.com/Connecting-Batteries-in-Series-or-Parallel).

[4] http://www.atmel.com/Images/Atmel-2549-8-bit-AVR-Microcontroller-ATmega640-1280-1281-2560-2561_datasheet.pdf

[5] The Atmel CPU for the Due and other boards have under-voltage detection too.


You can also use two 18650 batteries as they have a higher charge capacity

Each battery is about 3.7-4.2 V

That would be perfect for arduino....

  • Could you please edit your post and remove the "shouting" of all capitals? Also, do you mean 2 x 3.7V (7.4V)? For a homemade Arduino which may not have a voltage regulator that would be too high a voltage.
    – Nick Gammon
    Nov 14, 2018 at 8:19
  • depends, if you are trying to make a big project Nov 14, 2018 at 9:00
  • meaning like if you want the Arduino to power up all the components connected Nov 14, 2018 at 9:02
  • I'm not sure about homemade arduino Nov 14, 2018 at 9:02
  • ill check and let u know Nov 14, 2018 at 9:03

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