How to give power supply to gsm module?


I am interfacing simcom's gsm module SIM900 with Arduino.
First I have given power supply to gsm module from the Arduino i.e. +5V and GND. In starting days it worked fine.
But now it is working only on the AC to DC adapter (12V), That is why I bought 12V rechargeble battery. How to give power supply to my gsm module with the battery.

  • GSM Module has +5V pin only.

Battery specifications are:

Amptek Sealed Rechargeble Battery,
MODEL: AT12-1.3 (12V 1.3AH/20HR)

Constant voltage charge
Cycle use: 14.4 - 15V
standbye use: 13.5V-13.8V
Initial Current: less than 0.39A

Thanks in advance.

Hi Shivaaprs

Are you using an arduino shield with the SIM900 module or are you using the module directly? If you use it directly the datasheet states that it want 3.4 - 4.5 volts. I would think that most arduino shields would run on 5v and use a regulator to turn that down.

I think that supplying it with 12v will probably damage it.


It will also need perhaps 2A capable supply, GSM modules draw high current peaks
when transmitting, many times the receive-time current, and in pulses since the
GSM transmission is in time-slices. The peak current will be many times any
average current a multimeter would measure.