Yes, the battery is simple and quick to change. Full instructions attached, and below.

  1. Using a standard 2mm allen (hex) key (usually the smallest one on a typical Bicycle multitool) undo the screw in the center of the battery cover.
  2. Remove the cover.
  3. Replace the batteries with two SR44 or 357 type button cells. They must be silver oxide, not alkaline.  Make sure the positive face (+) is uppermost.
  4. Replace the battery cover. Take care tightening the screw, sealing is NOT dependent of screw torque. Slowly tighten the screw until it comes to a mechanical stop – do not tighten any further.
  5. Pass the magnet over the domed transmitted to stop the LED flashing light. If you do not complete this step, your batteries will drain quickly.