I generally work with 12V standard and simple DC wiring. Awhile back I put a bunch of LED lights on a bicycle for a Youtube video, though I ran them off of a single 9V battery. I would like to run two 9V batteries, but seeing as how this will result in 18V, I'd rather not blow out my lights.
Where and what size resister should I use so that everything works as it should?
Here is pretty much how the bike is set up now, if this gives you any idea: https://www.youtube.com/watch?v=iNgIvaooP88