I'm very new to Arduino and everything related but I'm highly interested to learn more. However, I've run into a problem right in the beginning.

I want to build some sort of portable emergency/notification button. One pushes the button and an SMS is sent or an HTTP call made to a server. I want to base this project on the Arduino Nano as it's quite small and therefore easily transportable. To have GSM/GPRS connectivity I found the SIM800L which seems quite suitable to what I have in mind. Now to the big question, how to power the Arduino Nano as well as the SIM800L on an portable power source, preferrably only one power source. From my understanding, the SIM800L requires a peak current of 2A when doing handshakes and sending signals. Is there any way I can power the SIM800L through the Arduino Nano, like Battery -> Arduino Nano -> SIM800L, or do I need to connect both the Arduino Nano and the SIM800L to the battery? Regarding the lifespan, for now it would be sufficient if I could press the button a few times and afterwards it'd stop working.


3 Answers 3


Check out

Thin battery to power arduino micro with nRF8001?

Also, I found a 6v battery (A544) at Menards that is about the same diameter as a AA, but is considerably shorter. It has 178 mAh capacity.

I haven't taken the time to test it, but I would guess it wouldn't have as much of a temperature issue.

It's not as small as the CR2032 in the above mentioned link, nor is it flat, but it's an option.

You might consider an Arduino Beetle. They are really super incredibly tiny and still 16mHz. I can't get any more info from where I'm at, but I'd believe they would use even less power than a Nano/Micro.

I found an Instructable that shows how to use a Beetle, a rechargeable 3.7v LiPo battery, and an HC-06 Bluetooth module. Sounds like it's equivalent to what you're looking for.



I did use a big electrolytic polarized capacitor in parallel with the sim800l power pins (like 470uF 16v) on an uno. It will handle the power on peak :)


When you are using a Arduino nano for your project you wont be able get the 2A current draw form the board.You have to use a external power source like a battery.You have to find a better battery with a considerable Ahs.

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