There's no way for LiIon battery to provide enough juice with our current setup.
Although our step-up converter declares up to 3A, and device consumes below 2A, we get unstable voltage when all sensors are plugged in. Working assumption is, battery's protection kicks in - device's inner resistance is just a few ohms.
And, so far device isn't exactly portable.
Anyway, we'll try with some good old dumb batteries. Although twice cheaper, they are much heavier, so we're not happy about it. Then again, step-up might not be required then.
But, we'll take a vacation first, and be silent for next two weeks or so;)