Falsely High humidity

[Kilo95]

I'm running a moteino r6 and weather shield r2. I've noticed for a while that it reads 100% humidity most of the time. (I've tried indoors/outdoors). Placed it next to another weather shield/mote which read ~60% humidity. If I leave it off for hours and turn it back on, it comes on at roughly the accurate reading and climbs over the course of 15-20min to 100%. All the other readings temp, press, etc we're almost identical. What's going on here? I've also noticed it seems to draw more power. I've got two 7.5F supercaps in parallel to power it. Charged them with a 3xAA pack with new batteries to 4.5v and it only lasts about 4 hrs. A single 7.5F SC used to power it.

[Felix]

Does the sensor return other valid readings? Or are they all performing similarly?
Could it be contamination of the die of some kind?
Would it behave any different if you just powered the Moteino from another source?
I would try changing some of these variables to observe if anything changes. It's a way to try tro divide and conquer the problem.

[Kilo95]

It does give valid readings for the other things (temp, pressure). I've powered off of a 3xAA with the same result

[LukaQ]

If anything like mine, your sensor is on a good way to die. My was reading (maybe it even was) 100% and sometimes it went under 100, but in few hours again back to 100.
In the end, it was reading more then 100%. BME and SI and similar sensor are not made for high humidity.
SI has heater inside, which if used, could prolong the life of the sensor, but reading are wrong when you have heater on and after you turn it off, readings will be low, until sensor settles (temperature wise)

[Kilo95]

That's kind of what I was thinking was going on

[LukaQ]

I don't know how expensive weather stations have this solved, but I know I wouldn't want to have membrane like sensor
I have to find time to test HS1101

[MojaveTom]

When testing the HS110x, perhaps the "touch" sensor of the M0 could be used to detect the capacitance of the HS110x.  Calibration would be fun.

http://ww1.microchip.com/downloads/en/DeviceDoc/atmel-42195-qtouch-library-peripheral-touch-controller_user-guide.pdf  Section 4.