jremington:
Since the transmitter will be used only very infrequently, just use a 9V block battery or 6/12V cylinder cell to power it.Those 433 MHz transmitter modules draw no current when not triggered (when the DATA input is LOW).
I want to use a li-ion battery so i won't need to use an regulator which will have a quiescent current too, beside the attiny
And my question is still here ? i'll be able to pull the data input HIGH with my attiny voltage (3.6-4.1) if the module will be powered by 12V ?