You should replace your QardioBase batteries if either of the following occurs:
If your QardioBase does not turn on when you stand on it or touch it with your foot.
Replacing the batteries on your device is easy. QardioBase operates using 8 standard AAA alkaline batteries.
To replace the batteries locate the battery hatch on the bottom of the scale. Simply push down on the tab to remove the battery hatch.
Replace the batteries ensuring they are inserted with the correct polarity. Simply slide the battery cover back on to snap it into place and your QardioBase will be ready to use.