I use the PLRF15 and 25 at work. Occasionally a 15 will stop working. We send it back (warranty) for repair or replacement.
We haven't had any issues with the 25s yet. Other than replacing the dying battery, have you checked your connections in the PLRF. Occasionally there is corrosion that can be brushed away with a toothbrush or removed with a sharp object (depending on the severity). Removing the battery when not in use, and keeping moisture out prevents this from happening.