Im adding a big chrome headlamp to the crashbar of my Vespa 50…mod style. Since i want it to actually work i would like to know what kind of battery i should use, where i should put the battery (dont have a glovebox cause i have a sparewheel behind the legshield) and how i can wire it to the lightswitches on the headset. oh and great if anyone knows where i can make the wires go without looking nasty. Thanks alot for any input! [:bounce:]

no.1,i’m assuming you have an early style vespa 50? pre pk 50?
now things get a bit complicated here!vespa lighting circuits are ac electric (alternating current) and batteries are dc (direct current).the two cannot be mixed,ie,you cant earth your light to your frameand expect to draw current from the battery and the engine electrics.the only way you could wire your light in to work would be to fix a battery somewhere on your bike,maybe a sealed lead acid type found in an alarm system hidden under your seat, wired through a double pole switch,maybe mounted on your spare wheel carrier,straight to the additional light.the dc current must not come into contact with any standard wiring.
next problem is charging the battery.either fit a rectifier device to the bikes wiring,which can be tricky if you aint electrically minded,or take the battery off on a night and charge it up.also make sure the circuit fed from the battery is protected by a fuse,usually about 5-10 amps,depending upon the size of the bulb fitted to the light.bare in mind that a small battery will not last very long compared to a larger battery.the aH (ampere hours) give a rough idea of how long it will last for.
sorry if this seems complicated but there really is no easy way to explain it.yes, i know the new vespas have a battery,but the battery only supplies the starter circuit,not the lights so you would end up with the same problem.
trust me,i’m an electrician!

don’t think so. you need a battery out of a fire alarm or intruder alarm system.RS componants or farnell componants stock them.
hope that helps

Thanks alot for your help! think i sortof got it. Im not english though so i dont really know what a sealed lead acid type battery is. And also not quite sure of what kind of batteries are in an alarm system. What about the sort of battery thats used for radio controlled cars and planes etc?
Thanks again