How about headlight? LED would be best right?

Since lighting for bicycles isn't regulated -- as it is for motorcycles -- it means more flexibility.

On my bicycles I use white LED modules found at the auto parts stores. The modules I've used are labeled as being accent lighting, they're an oblong module with 10 or so LED's and rated for 12 volts apiece. For each vehicle I buy enough to match the pack voltage, mount them on strips of metal and use U-bolts to mount that to the frame. For tail-lights I use red LED marker lights such as are meant for trailers. Same idea, each module is 12v so simply get enough to match the pack voltage.

The way I figure it on an electric bicycle you've got a significantly sized battery pack... so why not have significantly sized lighting? Why live with the dinky lights commonly used on bicycles?

The headlights I use are bright enough to illuminate the road.

Well I recently added a LED headlight to my E-Bike that runs directly off of the 48V of my E-Bikes 48V lighting system with no stepping down of the voltage. I have already finsished the tail/brake light version and will be installing it this weekend. It is of the same design, just more LEDs used so it will be not as bright as the headlight (I do not want to blind drivers behind me).

Here is a link to my thread, pics of the headlight is at the bottoms of the thread, just scroll down and click on the links to the pics.

http://visforvoltage.org/vehicle/%5Buser%5D/4407

I made the LED light by buying from Walmart a 120V AC 3.5 watt LED light and discarding the bulb base and the electronics except for the limiting resistors. I then rewired the rings to work off of 48V. I had to remove the largest outer ring and the smallest center ring for the headlight to be bright enough. The outer ring is my low beam, and the inner ring is my high beam. I also found out my E-Bike has the positive of the battery as the bikes ground and switches the negative for the lighting system and everyting else, just the opposite as standard automotive wiring (I popped 2 fuses figuring that out, LOL). My tail/brakelight is the same except the outer ring is my brake light and the inner ring with the smallest ring included is my drive light.

If you want a really monster headlight, and have 10 watts to spare, I recently discovered these huge LEDs: Vision X Solstice Solo

They put out 800 lumens, which is about half of an automobile headlight. And they accept anywhere from 9-50 volts, so you could hook them directly to a 48v battery.

I'm thinking of putting a pair on the forks of my scooter, since the stock headlight is pretty weak. But a single one mounted on a bike would be simply magnificent.

You are welcome Badger.

I bought a 56 led bike light off ebay for $8 and I am very pleased with it for the money, it's insanely bright and has three levels. Also search for 53 led as it's the same light.

Ebikes-ca has a real nice led light that runs on any voltage.

I'm doing some unofficial R&D on lighting right now.
The fact that these LED lights are direct voltage, you have a wide range of compatibility if you don't mind soldering.
Going off the bicycle battery is preferred. This concept is used by police on their bikes. They use the "Water Bottle" mounted batteries.
If you have an ebike that was factory made, it should have a connection for a flashlight lamp. Simply by switching this old school technology out for an LED mounted lamp on the handlebars, you will have a much more effective lighting system. It's very easy.

Nightrider and Cateye make some reputable lights. I use the Night Rider Ultrafazer on one of my pedal bikes and it is water resistant to 50 meters. The only draw back is that it is a little bulky when I take it off my bike.
http://www.policebikestore.com/lights.htm