My h23 is in a slip facing east. I have a 1.5 watt solar panel in my south window and this has worked fine for 3 years. We night sail alot during the hot summer months and the Admiral likes the radio/cd on most of the time. I have never had to put a charger on my single small Interstate deep cycle battery. I did change out all of my lights to LED a couple of years ago. Try it in a window