SIM800L operating current

Hi to all. I have some problems with this module (GSM SIM800L) and searching throught other forums did not resolved.

In serial communication with the module using an arudino MEGA 2560: when "AT" is send to the module, it responds with an "OK". After many "AT" are send, it stops responding and restarts.

The current and the voltage measured through the module were varing

The module was connected to the following circuits:

  • +5V arduino with two 1N51255A in series
  • eight AA batteries regulated with a LM317T
  • three AA batteries

I have no idea what else to try. A battery must be used so it can work with a GPS to send a SMS about the coordinates every 1 min.

Measure all voltages and post the values.

Voltages (in V):

93.8 – 93.1

37 – 59

13

Current (in mA):

4.29 – 4.21

4.35

4.47

Three AA batteries where used directly to the module

When current is around 37 - 50 mA, the module freezes and it reaches to ~93 mA.

It is the same when it is with eight AA batteries and two LM317 regulated to 3.8 V.