Excessive current consumption following transmission

[jzordan]

Hi everyone,
I am running some Arduino Uno's and uno clones with the RFM69HW 915Mhz using Felix's Rfm69 library with ATC enabled and the LowPower library to save power. The nodes kept in listen mode draw around 16mA while sleeping, and those with radio.sleep draw 0.3mA which is acceptable considering the regulators used.

I've now decided to make some battery powered nodes using arduino pro mini clones,  RFM69HW 915Mhz, and a Dht11 to start.  At first I was powering them with 4xAA through the onboard regulator and the arduino would restart following a transmission.

When powering the circuit with 2xAA batteries everything seemed to work fine, the data was properly sent and received. The next day I found the batteries had dropped below the brownout voltage. I found this odd (and fast) so I popped in some fresh batteries and measured the current draw of the system.

At power up it draws 5mA, then transmission starts and jumps to 80-90mA and stays at the current draw for the remainder of its operation even though the radio is put in sleep mode and the arduino powers down. I tried this using 2xAA, using the 3.3V from my FTDI adapter, and from the 3.3V rail from my arduino uno clone and all gave the same results. When operating the arduino pro mini without the radio, current draw was 5mA and dropped to <0.1mA during power down. When I reprogram the pro mini to stay in listen mode without transmission, the current rises to 16mA during listen mode and falls to <0.1mA during power down and radio.sleep.

Has anyone ever heard of this happening before? Any ideas of what it could be or how I could fix it?
It only happens the pro mini RFM69 combination following transmission.

I would eventually like to power the battery nodes with LiPo batteries and a 3.3v low dropout regulator, but at 80mA current draw this would be unfeasible.

Any guidance would help.

Thank,
Jordan