When I first recieved this controller, I wanted to wire it up to run some outdoor lighting at night. I already had a Xantrex C35 charging my battery bank with a 100 watt panel. This controller would have a smaller 15 watt panel connected to it. Wiring the C12 was a pain. The small holes youre supposed to put the wires into are rediculous. The battery + and - are right next to each other, and I was worried for a while they would short. It took about 2 days of trial and error to finally get it to work properly (Even though I had read the instructions on the controller case). The included instructions are pretty much useless and was more of a brocher than any sort of help. Now that its working, I can admit it works quite well. It is in sync with my C35 controller, and automatically turns on the lights when its maybe 30 minutes to complete darkness. In the morning, by the time the sun crests over the horizon, the lights turn off. Overall a good controller, but plenty of room for improvement. I thought this one would be fabulous after the perfect success of my C35, but this one doesnt live up to that. Unless you have EXTREMELY nimble fingers and patience, I would reccommend the MorningStar Sunlight. Bottom line, works like a charm, but takes quite a bit of work to get it working properly.