Light bulb voltage and watts

Hey Moped Army,

I have a really simple question from a newb. So I have a Vespa Ciao with a 6 volt system. I am my brake light just burnt out and I wanted to replace it. Yes I know I could just replace the bulb with a simple 2 buck bulb from treats (6 volt - 15/5 watt ), but I wanted to replace it with a brighter LED bulb as this is my taillight and safety is a concern of mine.

This is the current bulb:

However, when I look online, I cant find the exact bulb in LED form, for example I find amazon is close:

The voltage is the correct volt, but I am not sure about the wattage as it is not listed. I don’t know much about electricity. Simply put, I know that volts are the current, and Watts reference how much movement that the system can output. For example a car battery may be a 12 volts but the wattage on it is crazy high in order to turn over the motor.

So, i guess simply, when looking for a light, do I have to concern myself about the wattage as well as the voltage of the light, or should I just focus on the voltage?

Any ideas you guys have, I would appreciate it.



Re: Light bulb voltage and watts

The problem is these old systems run directly off the magneto generator coil which inherently produces an AC charge. whereas LED's are diodes and inherently poor in alternating current. That means without a rectifier to convert AC to DC, and usually also a battery to smooth the current, LED's tend to burn out quickly.

also watts are essentially power usage. since LED's are more efficient they make more light at lower wattage. that means in an unregulated system it can be easier to overload them also, and they burn out.

If you can find a similar watt LED it might work for a while, if you want to dig into doing it right with a rectifier regulator and charging system that's a good option, or for simplest direct replacement, get the stock replacements.

Re: Light bulb voltage and watts

it looks like those ruiandson B072DVQ1F2 ones will work with both direction current flow and may be OK in AC. I would say go ahead and try it. you'll want to use the same front and rear though. a regular incandescent bulb alongside an LED makes it dim

Re: Light bulb voltage and watts

If you have a blue wire ignition coil (exciter coil common wires through tail bulb) a LED bulb may or may not work without rewiring.

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