I am using a SIM800L Module with esp32. I am using a 3.7V 2800mAh lipo battery to power the sim800L but the LED is not blinking. I am lookng for answers in web but evryone seems to have a different problem than mine. In other case the sim800l is at least blinkng or blinked once. I have tested the led with multimeter and it glows so hopefully the board is okay. Is the power supplied by the battery is not sufficient? I followed this tutorial
I am sure about the sim card as it is a working sim card in INDIA (of IDEA) and works fine in my smart phone.