Homemade ebike lights

Woodsmoke

New Member
I’m looking at building up my own front light system using a led light bar. The one I’m looking at is a 30w light with a 10 -30v operating range. My bike has a 36v Yamaha Battery so I think I need a step down buck converter to get the voltage right but I’m not sure about the watts and amps.
Switching is another subject, weather I can dim the power for road use and how that can be done. Is that just a resistor?
I’m good at building things but my electrical knows he is limited! Any help greatly appreciated!
 

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Alex M

Well-Known Member
I would stay under 20W and under 1,500 lumen. Preferably with STVZO unit that you wouldn't have to dim.
 

Mr. Coffee

Well-Known Member
Region
USA
City
A Demented Corner of the North Cascades
I don't know if you are doing this to edify yourself about electrical systems in an e-bike, but if you just want a light you can get a pretty excellent light for considerably less money and time.

 
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indianajo

Well-Known Member
The buck converter produces 12 v @ 60 W. That is 5 amps.
The light has no specification for current or voltage shown.
2700 lumen seems excessive. I had been riding at night on a 100 lumen light until it went under water in my pannier bag. Since it was $40 I'm thinking of repowering it with a 3.3 v Li cell, with a simple toggle switch instead of that complicated microprocessor that had 7 functions.
 

Sierratim

Well-Known Member
I’m looking at building up my own front light system using a led light bar. The one I’m looking at is a 30w light with a 10 -30v operating range. My bike has a 36v Yamaha Battery so I think I need a step down buck converter to get the voltage right but I’m not sure about the watts and amps.
Switching is another subject, weather I can dim the power for road use and how that can be done. Is that just a resistor?
I’m good at building things but my electrical knows he is limited! Any help greatly appreciated!
You could use a resistor as a dimmer, but you'd be wasting energy in the heat generated by the resistor, not to mention potentially damaging anything that touched the hot resistor. Better to use an electronic dimmer. Better yet, save yourself a lot of time (and maybe some $) and buy some of the very affordable LED bike lights that are already available...just sayin'...
 

Woodsmoke

New Member
I don't know if you are doing this to edify yourself about electrical systems in an e-bike, but if you just want a light you can get a pretty excellent light for considerably less money and time.

Edify?! I’m trying to get a load of light but with out external power sources, I don’t mind the time, I like to tinker and the cost of the bits I’m thinking of are actually relatively cheep compared to many ebike specific lights out there.
I’d like a wide beam for off road use but most for sale are single spot types.
thanks for your input and time tho!
 

Woodsmoke

New Member
The buck converter produces 12 v @ 60 W. That is 5 amps.
The light has no specification for current or voltage shown.
2700 lumen seems excessive. I had been riding at night on a 100 lumen light until it went under water in my pannier bag. Since it was $40 I'm thinking of repowering it with a 3.3 v Li cell, with a simple toggle switch instead of that complicated microprocessor that had 7 functions.
Ah ha, 60 divided by 12 equals 5, I see! The light has a 10-30v working range and 30watts so 3-0 amps? Is that right?
I’m after a bright light solely for off road use, if I can dim it then on road but I have usb recharge lights for road use.
yeah 7 functions is just over the top!
 

ruffruff

Well-Known Member
I tried something similar except I tried using a step up convertor and taped into the 6V wire to the light already on my bike.
It would only light the smaller inner LEDs.

So I tried hooking it up to my DC power supply and gave it 12V. It flickered like a disco light! Not sure why and I have not had time to revisit it to figure it out.
 

indianajo

Well-Known Member
Ah ha, 60 divided by 12 equals 5, I see! The light has a 10-30v working range and 30watts so 3-0 amps? Is that right?
If the light draws 3 amps at 12 v, it would work with your buck converter.
You can use two timers, 555's, to make a switching dimmer, with a nfet to do the switching. Set one to be on for a hundredth of a second, set to other to be on from 1 hundredth of a second to 1 30th of a second, with a potentiometer in the RC timer. Enable the nfet with the first timer, the second is the dark time. The two timers alternate, obviously. Run as an oscillator. I build dip package projects like this on dip project board from farnell.com, newark.com in the US.
Or if you're a programming genius, you can do it with an arduino. Every computer I've programmed since the PDP-11 and the intel MDS8080, the computer sits there with a blank screen burning up power. My software never matches the computer or the PC host, for some reason, like not having a professional IT department to sort all that out. I bought an arduino, the vendor went bankrupt before I downloaded the free development software. Strike 8.
 
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Woodsmoke

New Member
You could use a resistor as a dimmer, but you'd be wasting energy in the heat generated by the resistor, not to mention potentially damaging anything that touched the hot resistor. Better to use an electronic dimmer. Better yet, save yourself a lot of time (and maybe some $) and buy some of the very affordable LED bike lights that are already available...just sayin'...
That’s good advice, no point wasting energy, I’ll look into electronic dimmers.
Ha ha, yeah alot of folks are saying I should just buy something ready made but nothing is taking my fancy that’s not over £200! A 6 volt light system seems under powered considering there is 36V available.
thanks for your input tho!
 

ruffruff

Well-Known Member
That’s good advice, no point wasting energy, I’ll look into electronic dimmers.
Ha ha, yeah alot of folks are saying I should just buy something ready made but nothing is taking my fancy that’s not over £200! A 6 volt light system seems under powered considering there is 36V available.
thanks for your input tho!
I just tried it so I didn't have to get into the internal wiring.
 

Woodsmoke

New Member
I tried something similar except I tried using a step up convertor and taped into the 6V wire to the light already on my bike.
It would only light the smaller inner LEDs.

So I tried hooking it up to my DC power supply and gave it 12V. It flickered like a disco light! Not sure why and I have not had time to revisit it to figure it out.
It’s a mind f*ck isn’t it. I’ve just been looking at a 9w 12 v led light bar so was then looking for a step up converter. There are some on eBay but i couldn’t find one yet that looked relatively sealed and Emtb suitable.
glad I’m not the only one trying this!
 

Woodsmoke

New Member
If the light draws 3 amps at 12 v, it would work with your buck converter.
You can use two timers, 555's, to make a switching dimmer, with a nfet to do the switching. Set one to be on for a hundredth of a second, set to other to be on from 1 hundredth of a second to 1 30th of a second, with a potentiometer in the RC timer. Enable the nfet with the first timer, the second is the dark time. The two timers alternate, obviously. Run as an oscillator. I build dip package projects like this on dip project board from farnell.com, newark.com in the US.
Or if you're a programming genius, you can do it with an arduino. Every computer I've programmed since the PDP-11 and the intel MDS8080, the computer sits there with a blank screen burning up power. My software never matches the computer or the PC host, for some reason, like not having a professional IT department to sort all that out. I bought an arduino, the vendor went bankrupt before I downloaded the free development software. Strike 8.
Dude I’m not afraid to say it but that went right over my head!!
 

Mr. Coffee

Well-Known Member
Region
USA
City
A Demented Corner of the North Cascades
Edify?! I’m trying to get a load of light but with out external power sources, I don’t mind the time, I like to tinker and the cost of the bits I’m thinking of are actually relatively cheep compared to many ebike specific lights out there.
I’d like a wide beam for off road use but most for sale are single spot types.
thanks for your input and time tho!

I mentioned that particular light because it has a very good reputation and is reasonably inexpensive (US $89.97). It is a wide-beam flood light that is well-suited for off-road use.

This video reviews both the Bright Eyes lights and the ionospherically expensive Exposure lights (starts at 7:13):


Like the video, I've found that for serious night riding (on road or off) you really want a flood light on your bike and a smaller spot light on your helmet. That lets you see around tight corners and also makes you much more visible to oncoming traffic. Since I won't ride with a cable connecting my bike to my helmet I'm committed to recharging batteries for the helmet light anyway, so recharging the on-bike floods isn't much of an additional hassle.

Last year I tried out a few bike lights (including that fancy Exposure Six Pack). I came to a number of conclusions:
  • Anything past about 2000 lumens is just silly overkill. A typical halogen car headlight on high-beam is about 1300 lumens, and LED or Xenon car headlights are from 2000 to 4000 lumens. A brighter light won't accomplish much for you beyond frightening wildlife.
  • Beam quality, at some point, is much more important than brightness. A spotty or inconsistent beam can be annoying or frustrating.
  • A decent helmet-mounted light will let vehicles see you literally kilometers away, even on a foggy coastal road.
  • Expect with any light to do a fair amount of engineering and re-engineering to get it mounted in a good place and making sure it stays in that place. Most e-bikes have pretty crowded cockpits so finding room and a good place at the same time can be a bit of a struggle.
 
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Alex M

Well-Known Member
STVZO? Why under 20 w and 1500 lumen, because of the trouble with the power delivery? Am I being too greedy?!
STVZO-compliant light illuminates the road surface without blinding the others: http://www.light-test.info/en/faq-en/169-stvzo-bike-lamps-regulations. They also tend to be more efficient per watt because the lumens are not wasted.

Under 1500 lumen because you are not on the ship :). And - yes, with 30W there could be energy problem re: battery capacity. 1500 lumen would be ~20W.
 

Woodsmoke

New Member
I mentioned that particular light because it has a very good reputation and is reasonably inexpensive (US $89.97). It is a wide-beam flood light that is well-suited for off-road use.

This video reviews both the Bright Eyes lights and the ionospherically expensive Exposure lights (starts at 7:13):


Like the video, I've found that for serious night riding (on road or off) you really want a flood light on your bike and a smaller spot light on your helmet. That lets you see around tight corners and also makes you much more visible to oncoming traffic. Since I won't ride with a cable connecting my bike to my helmet I'm committed to recharging batteries for the helmet light anyway, so recharging the on-bike floods isn't much of an additional hassle.

Last year I tried out a few bike lights (including that fancy Exposure Six Pack). I came to a number of conclusions:
  • Anything past about 2000 lumens is just silly overkill. A typical halogen car headlight on high-beam is about 1300 lumens, and LED or Xenon car headlights are from 2000 to 4000 lumens. A brighter light won't accomplish much for you beyond frightening wildlife.
  • Beam quality, at some point, is much more important than brightness. A spotty or inconsistent beam can be annoying or frustrating.
  • A decent helmet-mounted light will let vehicles see you literally kilometers away, even on a foggy coastal road.
  • Expect with any light to do a fair amount of engineering and re-engineering to get it mounted in a good place and making sure it stays in that place. Most e-bikes have pretty crowded cockpits so finding room and a good place at the same time can be a bit of a struggle.
Thanks dude, I’ve just woken up so I’ll have a coffee and digest!
 

Mr. Coffee

Well-Known Member
Region
USA
City
A Demented Corner of the North Cascades
Chain Reaction Cycles is having a clearance sale on many items right now. Including Exposure Bike Lights. So if you want one of their crazy-bright and fancy lights you can get them for 50 percent off while it lasts...

I have no connection to Chain Reaction Cycles.
 

FlatSix911

Well-Known Member
Region
USA
City
Silicon Valley
I have purchased a lot of bike lights over the years with a wide range of performance and price. ;)

Take a look at this model with dual LEDs powered by 2 lithium cells... the best feature is the battery level display and USB charge port for your phone.


1594596102564.png
 
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