Controller Light Output - Uses?

[WheezyRider]

True enough - I've not been on this forum long and already I am able to sort the wheat from the chaff (or maybe the salt from the vinegar?).

Anyway, back to the original posting - obviously most just use the 'light output' from the controller for ...... lighting. So guess what, I think I'll follow the wise and do the same.

AliExpress seems the most likely source (and I've scoured the site a number of times - but you get crossed eyes after a while) but I am a little cautious about which choice of light to go for in that I know that many of the cheap Cree LED lights have a very untidy beam pattern that can be disconcerning/annoying for other road users (and I know this is less of an issue for off-road use).

So if anyone can either give a recommendation or pointer (with links please) to a front light with a decent beam pattern, I'd be very grateful (and I'll not be going for the Busch and Muller type either - I'm a pensioner after all ).

Getting a decent front light is the first goal and then a good rear red light that will fit snugly on the pannier rack also.

Thanks in advance

Take the advertised number of Lumens with a big pinch of salt. You will see ludicrous numbers given for a lot of lights you can buy. A typical 5W Cree can give max about 700 lumens, yet you will see claims of thousands of lumens for a lamp with that LED. Then you will see lamps made of clusters of many 5W Cree LEDs and claims of tens of thousands of lumens. When you think about the amount of heat generated in that small space, there's no way those LEDs would even give their rated intensity.

Have a look for LED lamps with Cree XHP70. These are single LEDs capable of 4,000 lumens and they are higher voltage than standard LEDs. I saw some good lamps when I was looking late last year with these LEDs, but the sale didn't go through.

The technology is changing so fast now, I expect people will correct me with even better examples...

 

[vfr400]

True enough - I've not been on this forum long and already I am able to sort the wheat from the chaff (or maybe the salt from the vinegar?).

Anyway, back to the original posting - obviously most just use the 'light output' from the controller for ...... lighting. So guess what, I think I'll follow the wise and do the same.

AliExpress seems the most likely source (and I've scoured the site a number of times - but you get crossed eyes after a while) but I am a little cautious about which choice of light to go for in that I know that many of the cheap Cree LED lights have a very untidy beam pattern that can be disconcerning/annoying for other road users (and I know this is less of an issue for off-road use).

So if anyone can either give a recommendation or pointer (with links please) to a front light with a decent beam pattern, I'd be very grateful (and I'll not be going for the Busch and Muller type either - I'm a pensioner after all ).

Getting a decent front light is the first goal and then a good rear red light that will fit snugly on the pannier rack also.

Thanks in advance

Avoid the ones with a thick lens on the front. They're more like spotlights with a very narrow beam.

The silver ones with several LEDs are not bad.

 

[WheezyRider]

Avoid the ones with a thick lens on the front. They're more like spotlights with a very narrow beam.

The silver ones with several LEDs are not bad.

The lamps with two or three Cree LEDs with a good heatsink are ok, but this sort of thing drives me up the wall:



How can 15x about 700 or so ever get to 52,000? Then if each of those LEDs is 5W, the heat output must be around 60W. That heat has to go somewhere, and it's not like there is a big heatsink of the sort you would see on a computer CPU.

 

[sjpt]

Then if each of those LEDs is 5W, the heat output must be around 60W.

LEDs are around 50% efficient, so only 30w goes as heat. Still a lot.

I had thought it was over 80% efficiency but just looked it up and my memory had (as so often) served me wrong.

 

[WheezyRider]

LEDs are around 50% efficient, so only 30w goes as heat. Still a lot.

I had thought it was over 80% efficiency but just looked it up and my memory had (as so often) served me wrong.

I had it in mind they were about 20% efficient, but that was a few years back and the technology is improving so fast! My brain is too old and tired to dig out the equations to convert Lumens to Watts out, but I noticed from the data sheet, even to get just under 700 Lumens for a T6, you have to drive each LED with at least 2 amps at more than 3V, so more than 6 Watts (>3x15, or >45 Watts of heat) and to go higher (say 1000 lumens), to get absolute max ratings, 3 Amps at 3.35V, so about 10 Watts. So even if 50% efficient at max drive (giving 15,000 lumens), you'd be dissipating 15 x 5, ie, 75Watts, with no real heatsink other than the case.

https://www.cree.com/led-components/media/documents/XLampXML.pdf

 

[vfr400]

The lamps with two or three Cree LEDs with a good heatsink are ok, but this sort of thing drives me up the wall:

View attachment 37336

How can 15x about 700 or so ever get to 52,000? Then if each of those LEDs is 5W, the heat output must be around 60W. That heat has to go somewhere, and it's not like there is a big heatsink of the sort you would see on a computer CPU.

It doesn't really matter what they're claiming. One thing is sure: 15x CREE XM-L U2 will be bloody bright, when 1x CREE XM-L U2 is enough to fully light unlit off-road tracks.

 

[Bikes4two]

Avoid the ones with a thick lens on the front. They're more like spotlights with a very narrow beam. .........................

When the cheap Chinese CREE lights first started to become popular on UK roads, they were often criticised for the glare they caused to on-coming road users (including cyclists of course). So when I bought one I also bought a Fresnel Lens which gave it a nice horizontal cut-off similar to what you see from dipped car headlights.

This leans me towards my choice of new light having a similar lens arrangement to again avoid presenting glare to other road users. I take your point entirely about ending up with a 'spot light/(too) narrow a beam' though and 'too narrow/wide enough' is going to be subjective as well.

What fun!

 

[vfr400]

I take your point entirely about ending up with a 'spot light/(too) narrow a beam' though and 'too narrow/wide enough' is going to be subjective as well.

What fun!

Trust me, they're too narrow to be any use on a bicycle. I bought one, so I know.

 

[Bikes4two]

Thanks @vfr400 - I will heed your advice. What this thread needs is recommendations and pointers to lights that are a fair price, don't blind oncoming road users but give a useful beam for unlight road riding - anyone?

 

[WheezyRider]

It doesn't really matter what they're claiming. One thing is sure: 15x CREE XM-L U2 will be bloody bright, when 1x CREE XM-L U2 is enough to fully light unlit off-road tracks.

Yes it will! Not sure how long it will last though, due to overheating...or it may have to be down rated so much for current that it's not really any better than a smaller number of LEDs run at a higher current. The lamp was sold to run from a small 8.4 Li-ion pack, so if it draws the full potential 150W of power of 15 LEDs it would run out quite quickly. That level also is getting to the point where it would have a significant impact on your battery pack if you run it from the e-bike battery.

This lamp was for 15x XML T6 LEDs (I haven't looked up how that compares to the U2). On my bike I have a single XML T6 run from a 5V USB charger pack at about 1 amp and that does the job. If I went off road, maybe having a few of them would be good, perhaps at different angles to cover close and far fields. I have a handle bar extension ahead of the main handlebars, so I can get extra voltmeters, speedo, lamps and horn etc, etc

 

[WheezyRider]

Trust me, they're too narrow to be any use on a bicycle. I bought one, so I know.

I bought one with a fat lens that had a zoom capability that cast a good beam width, but it was a bit pointless, because you always wanted it on max width. The other annoying thing was that it had a single integrated 18650 cell at right angles to the lamp, so it was awkward on the handlebars...also, it wasn't that bright.

There is a lot of rubbish out there. If you see something you like the look of Bikes4two, post it on here, someone here probably will have bought on before and can give you a review, or at least an opinion (or three!).

 

[vfr400]

I bought one with a fat lens that had a zoom capability that cast a good beam width, but it was a bit pointless, because you always wanted it on max width. The other annoying thing was that it had a single integrated 18650 cell at right angles to the lamp, so it was awkward on the handlebars...also, it wasn't that bright.

There is a lot of rubbish out there. If you see something you like the look of Bikes4two, post it on here, someone here probably will have bought on before and can give you a review, or at least an opinion (or three!).

That's a different type. I was talking about the 60v ones with a buck converter in them and a massive bulbous lens on the front:

Pardon our interruption...

www.ebay.co.uk

 

[WheezyRider]

That's a different type. I was talking about the 60v ones with a buck converter in them and a massive bulbous lens on the front:

Pardon our interruption...

www.ebay.co.uk

Ah I see. Yes, no adjustment possible.

 

[Nealh]

For wired lights this type 100 lux I find excellent, the beam not overly wide but does light up your path nicely / very well, they are supposedly stvzo compliant.

Onature electric bike light headlight 100 lux input DC 12V 36V 48V 52V aluminum led ebike front light electric bike accessories - AliExpress 18

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[Bikes4two]

For wired lights this type 100 lux I find excellent, the beam not overly wide but does light up your path nicely / very well, they are supposedly stvzo compliant.

Thanks @Nealh - that's just the sort of unit I was looking for - order placed - hopefully it'll arrive before Boris or Xi Jinping fall out too much. I don't have a Busch and Muller unit to compare it with though (and I'm not likely to either ).

And the little red jobbie for the rear pannier.

 

[atheo]

For wired lights this type 100 lux I find excellent, the beam not overly wide but does light up your path nicely / very well, they are supposedly stvzo compliant.

Onature electric bike light headlight 100 lux input DC 12V 36V 48V 52V aluminum led ebike front light electric bike accessories - AliExpress 18

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

⁹Thats what I have fitted to my suspension bridge and find very adequate.

 

[Nealh]

Thanks @Nealh - that's just the sort of unit I was looking for - order placed - hopefully it'll arrive before Boris or Xi Jinping fall out too much. I don't have a Busch and Muller unit to compare it with though (and I'm not likely to either ).

And the little red jobbie for the rear pannier.

View attachment 37347

View attachment 37348

The rear light is excellent when it is dull/dark.
The 100 lux front I got was with the horn feature as well, so I use a Wuxing handle bar light/horn switch.

 

[joelectric]

I think what vfr was getting at is that when it gets wet, if the leads are not well insulated you could get a conducting path along the outside of the resistor.

However, my biggest concern is the amount of heat generated in a small space. It must get quite hot and I wouldn't like to touch it, or brush against it by accident.

Dropping resistors are ok for small indicator LEDs, but for high power lighting LEDs it's not a great solution, when 6 to 60V input bike lights are so readily available at low cost.

BTW Andy, do you think you could find a way of posting that is not so confrontational? Everyone has their own views and opinions, but for a forum to work properly, people need to express their opinions in a way that is not aggressive, confrontational or trying to score points off of others.

We want to encourage as many people as possible to get into e-bikes and if they go on a forum where people are tearing chunks out of each other, it is completely counter productive. Many people (especially women) will be put off posting if they see this kind of behaviour for fear that their posts will be torn apart by others.

There are ways of stating your points without upsetting others. I don't always get it right, but I do my best to try to accommodate the views of others and agree to disagree, rather than cause a pointless escalation.

Andy is incapable of being civil, he is a sad lonely man who gets his kicks out of insulting people and enjoying the carnage he creates.
If he spoke to someone like this in a pub. it would be the last time he done it.
Any decent moderator would have banned this troll by now.
So in the absence of any mods Andy is best ignored.

 

[RossG]

I have one of those twin cree set-ups, if I point the lights up to the sky on a cloudy night it lights up the clouds .. gets red hot too the whole light is one big alloy heat sink. Daft really but the only thing that matches it are vehicle LED headlights, now I can dazzle em back !

 

[MSG76]

Current is 2a max per pin & 60 vdc.

Hi @Nealh , sorry to barge in but also looking at getting a KT 17A to run at 36v with two light outputs. One from a 9pin 1t5 julet cable to front and a separate julet 2pin from the box.
Is the 2a max a standard in KT controllers per light output? Also, is this drawn from the total controller current or is it a passthrough from battery?
It seems it would be managed by controller but in this case if I'm in PAS6 and turn on both lights I should expect in best case scenario a current drop of max 2x 2a. Is this right?

Thanks for your help!