I've noticed something interesting, with the RFM69CW it's supposed to have 45mA TX current. With over-current protection in REG_OCP turned off I measured it at > 75mA! When I programmed REG_OCP to turn on over-current protection I had to set it to limit at it's lowest level of 45mA, I then measured just under 50mA. I notice that REG_OCP in the library is set at default of 95mA for this level.
I suspect this was due to a poorly matched wire antenna with non-ideal ground plane, but nevertheless people might want to set the REG_OCP value to 0x10 if they are using 45mA for their battery life calculations, the TX current may well be significantly more than you think.
Mark.