I am just following up on this project. Four years later the solar panels, solar controller, AC/DC converter, and even the battery are still working 100%. The battery always has a charge. I did make the mistake of leaving the lights on for several weeks while I was gone and the battery was very low, but not drained. Once I turned the lights off, the battery has had 12.5v all the time.
I see that four years later the Harbor Freight solar kit is still the same price - about $150 with the 20% off coupon you can get anywhere.
Don