[hvalentim]

hvalentim, now that you already have your TX v2.50 board fully assembled, maybe you could check by yourself the real current consumption of the unit

Without the fan and with just one sensor connected (DHT22 temp/hum) I am observing something like:

Board/Nano alone with wireless module -> ~20 mA
Additional max. consumption when reading from DHT22 -> ~8mA
TX Led on draw (20 mA led with 510R applied) -> ~13mA
13+8+20=42mA (a peak of 41,4 was observed)

It is not easy to give an average consumption value just by looking at ever shifting values but I would guess something around 30mA (perhaps a bit less) with this basic setting (not taking into account the solar controller, additional sensors, the Fan Led and the Fan itself, should they be used).