Way i figger--they work until they quit! I'd give up and plant lamps wired into the house current! By the time you get answers about lighting, in a lawn mowing site, you will probably have a long gray beard!
A friend gave me around 15 of those lights--said they lasted about one year, and they are junk. I proved that, when the junk yard gave me about 2 dollars for the aluminum that was in them.
Seems you could wire the house current types into one wire, then connect it to a photocell, and wait for darkness. Or a switch would work. RJ

Thanks Rusty! Finding a good message-board is not easy and I should have tried one of the others. I have undated with fair satisfaction (with what I found to choose from) and moved on to other challenges. There are always plenty projects around a house and solutions (not to mention an older house). A week is normally the most time I will allow and will have move with what I feel are my best solutions. You cannot get a project done by Just Talk But New Info Helps. Take Care!