Yes, I want to use white LEDs just because of the color (I know it has the highest consuption). I could use 2 batteries but I don't think it would be enough, even if I reduce to 10mA/LED it will only last for about 13 hours with one battery. As I described, I want to use the LEDs in different combinations (the "worst" scenario for the power when all 30 LED are turned on) and when it's daytime the LEDs will be on max (or bigger) load for brightness, when it us nighttime, the LEDs will be on minimum load. I don't want it to be wired, and don't have too much space.