Do not ignore symptoms that may be due to low or high blood glucose. If you have symptoms that do not match the Sensor glucose reading or suspect that your reading may be inaccurate, check the reading by conducting a finger stick test using a blood glucose meter. If you are experiencing symptoms that are not consistent with your glucose readings, consult your health care professional.

What kind of battery is in the FreeStyle Libre Reader?

The battery in the FreeStyle Libre Reader is a lithium ion polymer battery with a maximum rating of 1.4Wh.1

Reference

1. FreeStyle Libre flash glucose monitoring system User's Manual.