Ring Stick Up Cam Battery & Solar Panel

When I have a fully charged battery in my stick up cam & plug the ring solar panel in the cam battery goes flat whithin 2 hours with the sun shing brightly. When I bought the camera I was told to plug the solar panel into the cam with a fully charged battery and that the solar panel would charge the battery after the night of working on the battery . I'm stumped why the battery shows approx 90 % charge after a night & in the morning the battery goes flat in the sun light . Any ideas would be appreciated ...