How to reduce consumption of sim900 board (e-bay)?

Question

Do it yourself

Good day!
There is such a GSM module (sim900):
In standby mode, after registering on the network, it consumes 31 mA, which in my opinion is a bit much, especially for battery power. In addition to the module itself, the board has a MAX232, but according to the datasheet, it consumes no more than 10 mA. After switching the module to the battery saving mode (turning off the radio module), the consumption drops by about 1-3 mA.
Tell me where to dig so that it is more economical in terms of battery power?
Previously, he worked with Siemens TS35, and so he ate 9mA, he would have used it, but the dimensions are horse. And with sim900 ambush :(
PS: If suddenly someone has a schematic of this miracle lying around - it would be generally super

Answer 1

Command AT + CSCLK = 1 put
into sleep mode, should eat about 1-2mA
a lot of documentation
mt-system.ru/catalog/sim900
list of AT commands
mt-system.ru/documentation/spisok-komand-modulej-s...
sensible forum
electronix.ru/forum/index.php?showforum=130