Is accelerometer drift in the LIS3DSH normal behavior?

[Terence D]

I have an LIS3DSH securely mounted to a stationary object away from any vibration. Over the course of two and a half days, I've found the readings slowly change in value. I've tried this with multiple accelerometers (all LIS3DSH) and they always show similar results of drift.

Here's an example: It changed by about 0.006G on X, 0.009G on Y and .05G on Z. The graphs of change are shown below. Anyone have any ideas?

[Terence D]

One additional thing: Note that the magnitude drops over time as well. Ideally is should always be 1. Looking at the data graphed below, it starts at 1 and continually drops over the course of the two and a half days.

[RMain.1]

Did you ever resolve this behavior?

I am seeing something similar in our application, using the LIS2DTW. Further, I've seen significant drift, both when the part is powered for an extended period (e.g., the readings immediately after power up differ significantly over long duration - seem to 'wander' randomly), AND when it has been powered off for some time (e.g., the reading at shut down differs significantly from those immediately following power up when left powered off for a period of time one or more days.) I've tried both with & without setting the 'boot' bit during initialization - which is supposed to re-load factory trim values into registers. The data sheet DOES NOT MENTION which registers contain these 'trim values', although a note at the end of the register table indicates:

The content of the registers that are loaded at boot should not be changed. They contain the factory calibration
values. Their content is automatically restored when the device is powered up.

My guess is that the registers marked 'RESERVED in the range 10-1F contain these factory values. However, another note after this same table warns of potential permanent damage if reserved registers are changed (so I'm not about to blindly experiment ;-).