Oh, removing the battery fixes the accelerometer? I thought mine was permanently busted (normal reboot didn't help), and would have to be sent in for service if I wanted it to ever work again.

For me, as I recall from when it was broken, if I switched the accelerometer to full-scale mode (echo full >/sys/class/i2c-adapter/i2c-3/3-001d/scale), the X and Z axis could be seen off center by about 6 G (the Y axis was still normal), but otherwise appear mostly functional (and in normal scale, these values would of course get clipped to the normal-scale's maximum value of 2G). I imagined its calibration got messed up somehow, but there's no way to calibrate it from software, neither the Linux driver nor the lis302dl datasheet gave any hope of anyone but the factory itself being able to calibrate the unit.

Happy to find out that the accelerometer wasn't permanently damaged after all...