It consumes about 5mA of the battery with breathing light ON. You can further reduce the drain by disabling the breathing function for final retail version. (Note: unable to disable on prototype due to incomplete firmware).
All torches I have and I have several of them, have drainage below 0.1mA. All torches with an electronic side switch. Such a large consumption as FT02 has is a big drawback for me. It reminds me of Haikelite products, which also have such problems. I had HT07S HI and had 6mA.