DIY Lights - Results

forgotrafe

I decided to go DIY with my off-road light. Last night was the first time I tried it.

Because I couldn't find a suitable case I bought one of these off ebay. I've got the 30W 24deg bulb. £21

I then bought a power lead, o/s clamp, and grip nut off Lumicycle. £14

Finally I bought 2 x 7.2v 4300mAH radio-control car batteries (race packs), chargers & connectors, an in-line blade (car style) fuse holder off ebay. £64

Wired the batteries in series (to give 14.4v) to the power lead via the fuse holder and stuffed them in an old water bottle, taking the cable out of the drinking spout. A bit of foam pipe lagging stopped it all rattling about.

Because it's over-volted the light chucks out approx. 1300 lumens. Yes 1300! Most CREE LED systems chuck out a quarter of that. This thing is seriously bright. An unscientific test of lighting up the Ridgeway (remote & unlit) car-park I was in, suggested that the bike light was as bright, if not slightly brighter, than my car headlamps (normal halogen headlamps, dipped, not main beam).

Downside is that with the batteries I have it doesn't last much more than 75-90 mins before starting to dim. But then I guessed that'd be the case before I started and that duration suits me fine.

Plus side is that for a fraction under £100 I've got a light that is up there with commercial systems that cost twice the price. Money I've saved has paid for an Garmin Edge 205 cycle computer which I fancied but hadn't been able to justify before (except the flippin courier has gone and lost it).

If you've money to burn, want the sexyness of a commercial unit, don't like DIY projects or aren't comfortable with wire strippers then this route won't be for you. But if you fancy an amazing light for a fraction of the cost, you could do much worse than this.

Changes: I don't regret the way I did it. However, there are alternatives for the batteries - some ebay sellers are doing Li-Po batteries (though at a serious cost), my brother has several 14.4v 3Ah Li-Ion cordless drills so he's thinking of using a battery from those and you can of course get batteries as spares from the commercial light manufacturers (e.g. Lumicycle).

Hope that's of interest.

Rafe

forgotrafe

Two further comments:

1) I was doing 18MPH off-road at one point and felt the light was perfectly bright enough for that

2) If anyone wants any more info or pictures then just let me know

Rafe

Great Ayton

One 12V 30W halogen bulb running at 14.4V Will give you a light output of around 850 Lum assuming its a good quality bulb.

Expected run time from the system you have would be 1 hour 30 min give or take so your spot on with that really.

forgotrafe

Great Ayton wrote:

One 12V 30W halogen bulb running at 14.4V Will give you a light output of around 850 Lum assuming its a good quality bulb.

This is a Philps MasterLine Energy Saver. Philips reckon it's equiv of a 50W "normal" halogen. Sorry, should have made that clear.

Rafe

milese

Pics would be great!

Could you incorporate a switch to change the batterys from series to parallel to give a dimmer, but longer lasting light, or just a bit of flexibility if you realise your miles from home with only half an hours run time left!

Great Ayton

That was assuming you were using a modern efficient bulb. A standard old hat 50 Watt Halogen MR16 such as a Philips 37804-2 for example are only rated at just 790 Lumens.

forgotrafe

Great Ayton wrote:

That was assuming you were using a modern efficient bulb. A standard old hat 50 Watt Halogen MR16 such as a Philips 37804-2 for example are only rated at just 790 Lumens.

I can't find where I got the lumens from now! Though the maker of the light says the same I did find something else to back him up. The Philips catalogue says the bulb I'm using is 3300CD which Google Calculator says is 3300 lumen. Now I'm pretty sure that's not right!

Whatever, it's very very bright!

Rafe

forgotrafe

Pics at www.forgot.co.uk/photos in the MTB album. Wasn't sure what to take pics of - if I've missed anything then let me know.

Next time I'm out I'll try and take a picture of it lit. Someone on this forum posted a video with a 35W bulb, see more in this thread

I did think about the series/parallel thing. Have also thought about making an oscillator powered triac to switch the lamp on/off very fast (say 10Khz). I wonder if that would work & enhance battery life

Someone's made a controller for such lights here.

Any more info, please ask.

Rafe

Great Ayton

I think your correct that its wrong, One of these http://www.cateye.com/uk/product_detail/327 small bar mounted 4 AA powered lights gives 1500CD and runs for 90hrs. Here is a handy link on relations ships of different units of lighting http://teachers.web.cern.ch/teachers/ar ... s/all3.pdf It explains that there is no direct relationship between CD and Lumin. Video looks good though I made a similar set for some one I work with. I used two MR11 bulbs though. The RC cars batteries work very well as there really robust and cheap. You can use the cheaper LIPO batteries as your not using a high drain if you want. The ones used in RC cars are all expensive high drain and can dump over 3000ma in under 5 min, where as your talking a hour pluss

jabilcyclist

forgotrafe wrote:

Great Ayton wrote:

That was assuming you were using a modern efficient bulb. A standard old hat 50 Watt Halogen MR16 such as a Philips 37804-2 for example are only rated at just 790 Lumens.

I can't find where I got the lumens from now! Though the maker of the light says the same I did find something else to back him up. The Philips catalogue says the bulb I'm using is 3300CD which Google Calculator says is 3300 lumen. Now I'm pretty sure that's not right!

Whatever, it's very very bright!

Rafe

This is where I gave FORGOTRAFE the lumen figures.

http://www.jclighting.com/Technical/Lamp%20Types.htm

If you look at the 35w 24 deg Philips Master Line, it quotes 980 lumens. I reckon that’s at 12v. The one above shows a 50w standard lamp as putting out 1000 lumens, again at 12v. A 30w Master Line is said to put out as much light as a standard 50w, 1000 lumens at 12. Put 14.4v into a 30w Master Line and I’m sure 1300w is a feasible figure to quote. Bare (or is it bear) in mind that these calculations are taken for the chart in the link. The real test is in comparison with other bike lights. A 14.4v Philips may not have the massive run times, but they chuck out a lot of light.

I use a 15.6v pack with 20w and another pack with a 45w. Th e45w is blinding in term of light output. Awsome.

Mail me at cckbbr@aol.com if you have any questions about my lamps.

Sir HC

Get rid of the tamiya connectors (the ones you are using) and swap them for some Deans connectors as they offer less resistance.

What charger did you get with the batteries ?

jabilcyclist

Whose using tamiya connectors? The lamps I supply use 2.5mm x 5.5mm DC plugs and sockets.

Anyone keen on using Cree MR16 3w LED lamps?. They put out 240 lumens for their 3W power draw but really need to run on 13.2v or less packs.

forgotrafe

Sir HC wrote:

Get rid of the tamiya connectors (the ones you are using) and swap them for some Deans connectors as they offer less resistance.

What charger did you get with the batteries ?

I'm using tamiya connectors on the batteries. Though I find it difficult to believe they are that much of a problem in this situation?

I could get rid of the connectors altogether I think. The chargers (just trickle chargers, nothing fancy) have a thin lead coming out of them as well as the tamiya, as do the batteries.

Rafe

Sir HC

forgotrafe wrote:

Sir HC wrote:

Get rid of the tamiya connectors (the ones you are using) and swap them for some Deans connectors as they offer less resistance.

What charger did you get with the batteries ?

I'm using tamiya connectors on the batteries. Though I find it difficult to believe they are that much of a problem in this situation?

I could get rid of the connectors altogether I think. The chargers (just trickle chargers, nothing fancy) have a thin lead coming out of them as well as the tamiya, as do the batteries.

Rafe

All serious racers will get rid of them for deans or bullet connectors. I replaced the stick packs in the starter box for my 1/8th scale petrol car, there is a noticable difference when drawing high current. When you draw high current through the tamiya connectors, they do get warm and as a result can fuse together or melt the plastic.

Milkie

All serious racers will get rid of them for deans or bullet connectors. I replaced the stick packs in the starter box for my 1/8th scale petrol car, there is a noticable difference when drawing high current. When you draw high current through the tamiya connectors, they do get warm and as a result can fuse together or melt the plastic.

I changed my Tamiya's for Deans on my drifter, and the difference was noticable; but we are talking about high currents of 15-30amps.

Not sure it would make much difference if you are only drawing 3-5amps, although every little helps!

Not sure if this would work, but you can charge your batteries differently, so they have more punch(light)/less runtime or longer runtime/less punch(light).

Nice homebrew lights btw

supersonic

What is the weight of the whole shebang?

jabilcyclist

Bike lights tend not to be more that 35 watts which draw 3 amps. The most I use is 45 watts. Even at that, only 3.8 amps are drawn. Not a lot really, so I'm not sure if using tamiya connectors is detremental to the performance of bike lights.

forgotrafe

supersonic wrote:

What is the weight of the whole shebang?

Never understood this concern over weight - when I sit on my bike I add 14 stone to it. Kind of puts the weight of the various components/accessories into insignificance

But I like to be helpful so I just dug out the kitchen scales... Batteries in a water bottle plus fuse & lead weighs 950g. The light itself weighs nothing at all at less than 100g.

A Li-Ion or, if you can afford it, a Li-po battery would weigh a lot less.

Rafe

simbil1

jabilcyclist wrote:

Anyone keen on using Cree MR16 3w LED lamps?. They put out 240 lumens for their 3W power draw but really need to run on 13.2v or less packs.

I'm using 2 x 3w Crees and they are pretty good - each on its own 18650 lithium cell. Running from clipped on torches so the beam pattern isn't great. Depth is pretty good but need more close spread. I'm going to add another 3w on my helmet to see if that does it.
Ok on flat, but slows me for downhill and really twisty stuff.

I'm also thinking of making a 6 LED unit but am still investigating regulators and power sources.

supersonic

forgotrafe wrote:

supersonic wrote:

What is the weight of the whole shebang?

Never understood this concern over weight - when I sit on my bike I add 14 stone to it. Kind of puts the weight of the various components/accessories into insignificance

Rafe

Lol, it makes a difference to some, hence manufacturers are always trying to drop weight. I bet you could feel the difference between a 20lbs and a 30lbs hardtail after a day in the saddle!!!

jabilcyclist

simbil1 wrote:

jabilcyclist wrote:

Anyone keen on using Cree MR16 3w LED lamps?. They put out 240 lumens for their 3W power draw but really need to run on 13.2v or less packs.

I'm using 2 x 3w Crees and they are pretty good - each on its own 18650 lithium cell. Running from clipped on torches so the beam pattern isn't great. Depth is pretty good but need more close spread. I'm going to add another 3w on my helmet to see if that does it.
Ok on flat, but slows me for downhill and really twisty stuff.

I'm also thinking of making a 6 LED unit but am still investigating regulators and power sources.

How much voltage are you putting through them? I heard that 14v is the max but I've been running one on a 15.6v pack a few times. Hasn't blown up yet but I'm not sure of the long term effects. I guess overvolting does nothing for LED's, unlike my 15.6v 45W beastie.

simbil1

I'm driving them at 2.75 - 4.2 volts (18650 cell). You typically drive them at 3.7 volts and to go higher is risking damaging the LED. LEDs do not like heat so need to be well heat sinked or run conservatively (no more than 3W for P4 Cree's).
I think driving at 8 volts or more will fry the LED - I've heard of them dying at 7.2v direct drive. Are you direct driving or is there some regulator circuit - I guess the latter otherwise it would be smoke!
You can get cheap reflector + regulator + p4 cree here that takes a reasonable spread of input voltage:

http://www.dealextreme.com/details.dx/sku.1343

Also a great site for cheap rechargable lithium cells.

jabilcyclist

I'm using one of these

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=010

Bought one of these to try. Same Cree, different tpye MR16. Will modify my lamp to suit.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=010

I make my own lamps as you know, and plug a 15..6v NiMh battery directly into the lamp. No heat generated. Lamp always runs cool. Why do so many mention heat? Am I missing somthing here? I assume, perhaps wrongly, that if my lamp is cool them the bulb too is cool, and OK?

I'm more a halogen man, still learning LED technology.

Great Ayton

jabilcyclist wrote:

This is where I gave FORGOTRAFE the lumen figures.

http://www.jclighting.com/Technical/Lamp%20Types.htm

If you look at the 35w 24 deg Philips Master Line, it quotes 980 lumens. I reckon that’s at 12v. The one above shows a 50w standard lamp as putting out 1000 lumens, again at 12v. A 30w Master Line is said to put out as much light as a standard 50w, 1000 lumens at 12. Put 14.4v into a 30w Master Line and I’m sure 1300w is a feasible figure to quote. Bare (or is it bear) in mind that these calculations are taken for the chart in the link. The real test is in comparison with other bike lights. A 14.4v Philips may not have the massive run times, but they chuck out a lot of light.

I use a 15.6v pack with 20w and another pack with a 45w. Th e45w is blinding in term of light output. Awsome.

Mail me at cckbbr@aol.com if you have any questions about my lamps.

Looks good. shows how far out of date a am lol

simbil1

jabilcyclist wrote:

I'm using one of these

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=010

Bought one of these to try. Same Cree, different tpye MR16. Will modify my lamp to suit.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... :IT&ih=010

I make my own lamps as you know, and plug a 15..6v NiMh battery directly into the lamp. No heat generated. Lamp always runs cool. Why do so many mention heat? Am I missing somthing here? I assume, perhaps wrongly, that if my lamp is cool them the bulb too is cool, and OK?

I'm more a halogen man, still learning LED technology.

I'm not sure if those lights are regulated or not, but a triple cree assembly would probably be OK running directly off 12v (depending on how the unit is wired). If you can supply 12v from your battery set up, it would be best.
That kind of assembly is probably going to be good in the heat sink department so should be OK. LED lifetime is really good unless they are run hot. If you don't mind a reduced life time, you can run them hard! The benefits of running them hot are small though, so it makes more sense to run them at the correct input range.
An alternative to running a 12 volt house light, is to get this kind of thing:
http://www.dealextreme.com/details.dx/sku.9358
It's regulated, so you just need to supply a voltage in the range 3.6 - 9v. The input range targets common lithium cells (using 1 or 2).

RidefastRidefree

made a set a few weeks back
trick for casing is plumbing fittings, ill try n get some piccies up.
using a 2W-ish LED and a 50W for descending pumps out for more light than my lumis ever did. advantage of LED is i only need a small battery pack, so all shambam cost me about £40 to make. BARGAIN!