We have heard from Blues several times that Blues has been able to achieve syncs of small Notes <1 kB with about 10 J of energy. But we have never been able to do better than about 20 J per sync. Here’s a picture of our Joulescope during a pretty typical sync where you can see we used 19.1 J of energy.
Can you describe what hardware setup you have? Perhaps that will shine some light on the power consumption you are seeing.
Which Notecard/Notecarrier combination are you using? Are these used in isolation, or are you also running a host MCU off the same battery.