Hi @jsearlePSU_ARL ,
I wouldn't expect battery affecting the measurement, but possibly vehicle response (although not at 34%). The default params are setup for 4s as well.
When batteries get low, 'power' gets low, and thus response, so the oomph to move to desired location, but not the sensors ability to measure (that power source is from the VOXL power module output, not tied to the motors power per-se).