Why is the web site reporting that my WRTU battery is discharging?

Why is the web site reporting that my WRTU battery is discharging, but the unit power supply is plugged in, and the WRTU power LED is showing GREEN?

The DC power supply is providing DC power to your WRTU, but not at a level strong enough to keep your battery charged.

The power supply may need to be replaced. Please contact RACO through either the "Ask a Question" tab above or 1-800-449-4539.