Test it out. Start low, work your way up till it reliably lights every time. Asa general rule though, start with the rated wattage and go from there.

good call. since i dont have anything to really change the amount of voltage/current with other than using aaa, aa, 3.6v and 9v batteries, should i buy a potentiometer if they dont work? because by adding a 100v cap or a 250v cap (2.2 microf and something else) i'm sure ill be able to get it eventually, but it seems a pot would be more efficient, so i could not waste the battery as much by using only what was needed. should i just use straight batteries, or pretend i'm cool and use a pot?

batteries should be fine... you don't really need the caps either, unless you're making a slapper detonator.

okay that makes it easier.

unless a slapper detonator works better? whats a slapper detonator?

means where a BIG cap is discharged into a specially shaped b***** wire which vaporises, and the little bit of semi-nuclear hot plasma dets the explosive.