Hi @chey, no, with the pro minis and MySensors lib I couldn't get less.
Didn't measure with yet another multimeter though...
My battery sensors are working now for about a year and the battery levels are between 65% and 70%.
The sensor furthest from the gateway is at 65% and the 3 others at 70%.
Not bad I think.
https://forum.mysensors.org/topic/11499/checking-mechanical-locked-doors-by-a-battery-based-windows-door-sensor-node
