Replacing bulbs with LEDs: considerations?

[Warthog]

I have been considering replacing my XR4 headlight for a higher out put. In order to reduce the likelihood of having to replace an alternator for about £100, I have decided to start by reducing the draw but substituting my other running lights for LEDs. I have found a US company that makes direct replacement LEDs.

Given that I have fitted a blinker set to my XR, I am concerned that if I replace a 21W bulb with a 3W LED, will the relay make them blink stupidly fast like when one of the indicator bulbs blow?

The website I'm looking at says that you need an LED compatible flasher unit, or parrallel, in-line resistors to siumlate a filament bulb, but surely that would bumpup the wattage back to the level I'm trying to reduce....

[Lumiya]

There's lots of old threads on LED indicators on this site if you do a search for it but here's a few quick answers to your questions.

Most Flasher units are current dependant for flash rate so yes you might need a LED compatible flasher.

Yes if you put in ballast resistors you are drawing the same current as a normal bulb

Watch out for your dash indicator bulb as if it's a single cross wired bulb it'll mess up the timing/voltage (See this thread)

Kymmy

[Warthog]

Thanks for that!

Will investigate....

[Austin]

Replacing indicators with LEDs won't make much difference to current drawn - they're on, oh no they're off, on again, off, on,off,on etc.

Replacing clocks lights only saves a few watts - eg 3 x 1.5watt (or 3W) bulbs with virtually 0watt LED isn't saving much either. What's your alternator output? Then compare with that with bulb consupmtion and allow about 100W for ignition circuit.

I run 2x55w fog lights and heated grips over and above standard lights and ignition and my TA is fine - the alternator makes 375watts (from memory) and I still reckon I have 40-50+watts in reserve.

[Lumiya]

Replacing indicators with LEDs won't make much difference to current drawn - they're on, oh no they're off, on again, off, on,off,on etc.

Replacing clocks lights only saves a few watts - eg 3 x 1.5watt (or 3W) bulbs with virtually 0watt LED isn't saving much either. What's your alternator output? Then compare with that with bulb consupmtion and allow about 100W for ignition circuit.

I run 2x55w fog lights and heated grips over and above standard lights and ignition and my TA is fine - the alternator makes 375watts (from memory) and I still reckon I have 40-50+watts in reserve.

Some bikes push thier generators to the limit, others don't. Only way of telling is to measure the ampage given off by the reg/rect at speed and then measue your complete current drain with all your electrics on.

But yes as Austin says most of the bikes will cope with extra current drain without the need to take drastic action.