Originally Posted by comradehoser
okay, so what is the advantage of overvoltaging, really? I just did it because I could, but...
Am I basically just burning stuff out faster?
I thought there would be some sort of gain for battery life, but if I'm busting aH and heat like a 50w party, why don't I just run a 50watter in there at a marginal extra expense if the housing can take it? I could save a little weight on the batts, too.
Better efficiency. A given bulb run at 10% over its rated voltage uses about 20% more power than at its rated voltage ... but delivers 35-40% more light. At 20% over rated voltage you draw about 25% more power than at rated voltage but get about 80% more light. The downside is reduced bulb life, but if you're reducing a rated life of 3000-5000 hours to a few hundred hours, a lot of cyclists consider the tradeoff to be worth it.
http://nordicgroup.us/s78/wattslumens.html
See the above link for a chart of wattage and light output at various drive states. I believe the lumen figures in this chart are actually wildly optimistic for halogens, but the relative values for rated vs. 10% over vs. 20 % over should be correct.