this is exactly what i am looking for.I have a red light that mounts to my scope and is powered by a 12v feeder battery--it's good for about 80 yds, but my hogs are "red-light scared" and if I am not super super slow bringing the light down on them, they scatter.
I have also put the solar-powered landscape lights on the t-posts of the feeder pen, pointed under the feeder. They are AA-battery powered, have a small solar panel and electric eye for on-off. I have 4 of them and I can see the hogs from my seat 70 yds away without the red light. I got a pair at WM for $20 and bought a second pair at Harbor Freight for $15. This is way cheaper than some of the specialized hog lights. They've been up and running since May and the only problem I've had is from cows scratching on them--they are plastic and not real strong. But, a roll of duct tape fixes them just fine.
Here's a current link to Harbor Freight's product--looks like the price went up a bit: