Originally Posted by
unterhausen
I'd be happier with full power, but at the prices they are selling at I am interested enough to try to find out if I need any more power. No point in having more power than I need
A computer USB port is 2.5W. 1.5W isn't enough to even charge a phone. Considering the cost of building a wheel anything under 6W probably isn't worth the money. Most modern LED headlights are ~100 lumens/W, halogens are more like ~30-40 lumens/W. That should give you some idea.