Choosing a EBike Headlight

Choosing a EBike Headlight

Choosing a EBike Headlight - Intro

EBike have variable voltages 12 volts, 36 volts, 48 volts . . . . .and more exotic. So you would think that finding a headlight would be tricky, but with some very simple wiring and a few bits from EBay there are tons of ways to get a great headlight on your EBike.

LEDs are the light of choice as the use the least energy.

Very Bright - Can be Dangerous Dazzling Other Road Users

Choosing a EBike Headlight - A "Universal" Light

If you have deep pockets Busch and Muller make a EBike Headlight that takes 24v - 50v it is that easy. Just connect it up and away you go. But these lights cost £50 / $80 upwards so pretty steep.

However if you look hard on ebay you can find a Chinese equivalent for £5 / $8. There is no set term for these lights but try "universal scooter head lamp" or "universal ebike headlight".

NOTE: One important difference between a high quality Busch and Muller lights and the cheapo chinese versions is that the Busch and Muller Ebike lights have an excellent beam pattern, that is to say 95% of the light goes on the road ahead, and not up in to the sky, or in to oncoming drivers eyes. An 80 Lux Busch and Muller light will draw 3W and yet provides so much light on the road it compares to a 15W light that splashes light all over the place.

Choosing a EBike Headlight - 12V Lights

By far the most popular volatge for lamps and headlights (of any type) is 12V, this is because cars and 4x4s etc. use a 12V system, so there are plenty to choose from trying searching for "12V LED work lamp" and you will see for off road use there are some amazingly bright lights that will run off 12V.

I would not recommend any thing more powerful than 3W for on road use, as you will dazzle oncoming drivers. Of course you could set up a big headlight for off road, and a smaller headlight for onroad use.

But the problem remains that you have a 24, 36 or 48 volt battery, and a 12 v headlight, so you need to provide a 12 volts supply. . .  .

Choosing a EBike Headlight - Supplying 12V 

These lights do not use a great deal of energy especially is you keep under 5W, they will run for 12 hours on a 12 ah battery.

Choice 1 - Separate Battery

Although this complicates charging it also means that you will not be taking power from your main battery. You could choose a 12V SLA battery and charge with a cheap charger, or there are lithium 12v offering that although expensive do not require constant charging as they do not self discharge.

The choices (2 and 3)  below without spending a lot of money are limited to about 1amp current, which means another advantage of a separate battery is that  you can run very powerful lights.

Choice 2 - Variable Voltage Regulator

This a great choice, you connect you main battery (24v, 36v , 48v) one side and adjust the voltage to required which could be 12v or 6v if you wanted to re-use some older dynamo lights. You can choose. Most of the cheaper regulators are limited to around 1amp current of a 10W (at 12V) LED headlight.

Choice 3 - Buck Converter

A buck converter will drop a set voltage say 36V to 12V so you can run your headlights, this is probably the easiest option. Make sure you choose the right volatge, most reasonably priced buck converter will kick out about 1 amp so you are limited to about a 10W headlight.

Illustrator Devon