How to provide enough power for SIM800L/SIM800L V2 GSM module?

Hello! This is my first post here, on this forum, so I hope I choosed proper forum section.

I'm doing some project based on Arduino Uno, some sensors, LEDs, buzzer etc. I want to add GSM module and see that SIM800L / SIM800L V2 should be enough to send SMS.

I read that these modules should be powered via external power source, and peak current can reach even 2A.

I have some AC adapter - 5V, 2A. If I choose SIM800L V2 and add this connector:

then it will be working properly?

But when I choose SIM800L, then I need something like this: LM2596 DC-DC converter to adjust lower voltage from 5V to ~4.1 V right? But what about current? Will it lower together with voltage?

Thanks in advance for any suggestions.


Does your specific module take 5V as input? (not all do!) If yes, it'll work fine. Do consider adding a large capacitor near the SIM800L (right at the board) to help stabilise the voltage.

If no, you may indeed add a buck converter - make sure it can supply sufficient current.

I ordered SIM800L V2 which takes 5V input :slight_smile:

But I would like to power up all the things from one power source. I thought about buying AC adapter 5V/3A-4A, using DC connector and power all from the contact board, but when SIM800L V2 takes 5V as input, Arduino takes 7-12V when using external power source.

I thought about using short USB-A <> USB-B cable, cutting off USB-A connector. Then I could plug 5V and GND from this cable to the contact board and power supply UNO this way. What do you think about it?