Trike Lights




This is a how-to for a set of lights for a recumbent trike. The system consists of 3 headlights and 3 taillights, all running off a central power block. It is capable of being run off a variety of batteries (as long as there are at least 7.2 volts) as well as bike generators (12 volt 6 watt type). I decided to build this system because it is much more powerful than typical bike lights and much cheaper than the high-end systems.

Check out the web site:

Step 1: Parts List

Here is the grand list of parts!

-Clear bullet lights
-Red bullet lights
-Large red bullet light with fins
-Large white bullet-style bike light
-Red LEDs - Digikey part 67-2061-ND
-White LEDs
-White LED Resistors
-Red LED Resistors - Digikey part TWW3J8R2-ND
-Two battery holders - Digikey part BH24AAW-ND
-Waterproof project box - Digikey part HM954-ND
-Power switch - Digikey part CKN1019-ND
-Five volt regulator - Digikey part 296-8157-5-ND
-Bridge rectifier - Digikey part VS-KBPC108-ND
-Circuit board - Digikey part 3405K-ND
-Soldering equipment
-Epoxy; caulk or hot glue would probably work fine as well

Note: Not all parts are pictured.

Step 2: Disassemble and Remove Innards From Lamps

First disassemble all the lamps and remove the existing light bulbs and wires.

Step 3: Solder Wires to LEDs

You'll want to solder some wires the the LEDs. The white LEDs have solder pads built into the heatsink, but the red LEDs just have straight wires coming out of the acrylic. You may want to test the LEDs after soldering to make sure they're not heat-damaged. There is a photo of me testing a recently soldered LED.

Step 4: Mount Lights in Lamp Enclosures

This step really isn't that difficult. You thread the wire through the hole in the back of the lamp, put a dab of epoxy/hot glue/caulk on there, and let it dry. The wires holding the LEDs are plenty enough to keep them in place, and the epoxy waterproofs the entry point of the wires. Let the glue dry with the lamps held in place by a clamp so the glue doesn't drip down the metal casing. After the glue has fully dried, you can fiddle with bending the wires a bit to make the lights point in the direction you want.

Step 5: Build Power Electronics

Assemble the power electronics as shown in the schematic diagram. You'll need to get everything to fit onto a 2" by 2" board or it won't fit in the project box (even then it's a little tight). Pictured is the almost-completed circuit. It lacks the white LED resistors. The heatsink for the voltage regulator is probably optional, but I had some sitting around and thought I'd play it safe.

Step 6: Add Insulators

Now you'll need to add insulators so that the circuit board and battery casings don't contact the metal project box. This step is not necessary if you use a plastic box.

Step 7: Add Power Switch

You'll need to add the power switch to the project box. A 1/4" drill bit is the perfect size.

Step 8: Put It Together

Finally, solder on some wires to carry the power out of the box, drill a couple more 1/4" holes for the wires, solder the battery holders to the circuit, and cram it all into the box! The wires coming out of the box carry the correct voltage for the LEDs. I color coded the wires: red wire for red LEDs, green wire for white LEDs (pictured coiled inside the box, not coming out of the box, I had not yet completed the white lamps), and black wire for ground.

Step 9: Carrying Case

You'll need a bag on the trike (or bike) to carry the electronics box. You'll also need to run wire to all the locations where you want lamps. I used 20 guage lamp wire held in place with black zip ties to match the color of the trike frame.

Step 10: Mount the Lamps

You'll need to mount the lamps. This will vary for different trikes, but I included some pictures to give the general idea. I used crimp connectors to connect the lights to the wires. Eventually I am going to cover the crimps in heat-shrink plastic.

Step 11: The End

That is it. Now all that remains is to ride! These lights are extremely bright, so bright that you may want to disconnect some of them when riding on a trail, as they could annoy other trail users. The project as described here will accept any battery or combination of batteries as long as they are at least 7.2 volts, and it will also accept bike generators of the 12 volt 6 watt variety. The parts all fit in the project box, but it is a tight fit; this keeps the parts from rattling around while riding. Enjoy!



    • Trash to Treasure

      Trash to Treasure
    • Tape Contest

      Tape Contest
    • Arduino Contest 2019

      Arduino Contest 2019

    16 Discussions


    10 years ago on Step 5

    In Step 5, what is the purpose of the bridge rectifier? If you are bothered about damaging the circuit by accidentally putting a battery in wrongly, I would simply put in a single rectifier. If you're not bothered about putting the battery in the wrong way because you can't (I have a similar system on my bike but I leave the battery permanently connected and charge from a wall charger via a resistor and polarised DC connector. I have a blocking diode on that to stop both reverse current and the charger being accidentally the wrong way round. The disadvantage of putting the bridge rectifier in the primary light circuit is that it is giving two diode drops across it and will be wasting approximately 2v of the battery voltage. Putting in a single diode will at least limit the drop to 1v and also save you some money. However, if you are driving it off a dynamo it is obviously necessary, although then I would also put in a capacitor after it to smooth out any flicker.

    4 replies

    Reply 10 years ago on Introduction

    The plan is to have a dynamo as a power option, even though it is not currently in use. Ideally, I'd like the ability to switch between batteries and dynamo. Caps would be nice for a dynamo powered system, but the flicker isn't really that bad, barely noticable.


    Reply 2 years ago

    Interestingly, I'm just about to update my system. I've just bought a Shimano dynamo hub. I am planning on basing my system on 5v as the dynamo is 6v 3W.

    I will be using Schottky diodes in a bridge rectifier feeding into a 4xC type NiMh battery pack @3.6Ah total. Off this I will be taking the lights and a USB connector for charging phones or tablets and adding another optional mains adaptor charging socket.

    I've decided to go for this as sometimes I go out bike touring and keeping a phone charged is a problem. I was originally looking at carrying a solar charger but here in the UK it's not too reliable. Plus, the battery pack will be being charging even when I'm not actually using it so I will also always have lights and can then charge the phone off it even if I'm not riding. I am also thinking of using a single Schottky diode feeding into the lights or a couple of separate lights front and back so they will always be on whenever I cycle.


    Reply 10 years ago on Introduction

    Thanks for replying. On my bike, I use 2D cells on my current system. You can get them at up to about 10Ah which means they last a long time. The light I use for seeing by is a modified 3W torch which used 2D cells via a DC-DC chip. It is 3W Cree LED based and very very bright if a little narrow. I also use a standard 3v flashing white bike light to be seen by at all angles and a rear red flashing 5 led light. Total consumption including back light is less than 1.5A so it will give a long time of use. I originally had a bottle dynamo system but I prefer this as the drag from a bottle dynamo was not fun plus I can switch out the 3W Cree for when I am on lit roads and only need to be seen! However, I had a bike a long time ago with a hub dynamo and that was superb, very little drag if at all in real terms, it would be brilliant at keeping this charged and probably allow smaller batteries to be use..


    Reply 2 years ago

    On my bike I have laptop battery powering all my lights which include a combination brake/tail light, headlight with hi/lo beam, front and rear signals.In my area signal lights have to be at least 500mm apart or 50 cm. A fully charged battery will run the lights for approx. 600 hours. When i have to charge the battery I just take it off the bike,plug it into a USB port on the home computer

    i made these. however im not sure if i need a driver. i got two 3.7 volt batteries in parallel they allegedly put out 2400 mah but my leds put max output at 1000 MAH and im using the reflector as a heat sink


    8 years ago on Introduction

    this one has nothing to do with your lights but i was looking at your trikes and was wondering what you did for your front axles


    Reply 10 years ago on Introduction

    I post there on occasion! Although I'm not the primary author there heh.


    Reply 10 years ago on Introduction

    If you're admitting that these are not photos of your work and you've just copied them because they look good - you should take them out and replace them with photographs of something you did do. It's not right if these ain't your trike!



    Reply 10 years ago on Introduction

    Nono. My boyfriend (the photographer) and I built it together, it's our trike. The site is our blog.


    Reply 10 years ago on Introduction

    Thanks! Although I'm not the photographer so I can't claim credit there. :) The photographer is the other author at the Steuben's Wheelmen blog.


    10 years ago on Introduction

    Rather than using power-robbing resistors, I have been using the more-expensive (but more efficient) constant-current DC-DC converters such as the buck- and boost- "puck" line from LED Supply. Because they are constant current, you can wire your LED's in series and use only one converter per string. The "buck" converters step the voltage down, so if you take all the LED's in series and add up their forward voltages, you need about 1 volt more than that for an input voltage. The "boost" converter increases the supply voltage, and you'd need a supply with less than your forward-voltage sum minus 3 volts.

    You can also run identical LED's in parallel (i.e. use a buck converter with 3 red LED's in parallel) but the current is distributed to each LED equally (as long as they have the same forward voltage drop). Thus, 3 LED's with a 1000mA converter will drive each LED at about 333mA.

    1 reply

    Reply 10 years ago on Introduction

    Thanks for the comment! I do know about the efficient DC-DC converters, but the problem is that I determined that each LED would need it's own converter. I can't connect the LEDs in series because I want to retain the ability to add/remove LEDs while on the trail (via little plugs I can unplug). If they're in series, I'd lose the whole set of lights!

    I could do parallel, but it is actually not a very good idea to connect LEDs in parallel unless you are sure they came from the same batch. Technically you can do it, but it can shorten their life if they have minute differences in their voltage drops. Constant current power sources are out for parallel LEDs because I want the ability to add/remove LEDs on the trail. If the circuit is built for 3 LEDs and I remove one, the current would be all wrong. But yea, "officially" (officially being defined as according to my analog devices professor), connecting LEDs in parallel=bad unless you are sure they came from the same batch/substrate. Even identical LEDs from the same supplier are different from batch to batch.

    So yea, I do love the idea of using DC-DC converters, but really I'd like one for each LED so I can configure which lights are on/off. (For example, on the trail I just use one of the 3 tail lights because there are no cars on the trail and having all 3 is bright enough to annoy other trail users.)