Bowie69 Posted September 12, 2015 Share Posted September 12, 2015 Well electronics don't like much about 80C long term, maybe 130C depending on make up. Cooling something 500C is easy, air will do it, as temp difference is huge, cooling something that is 80C with 30C air is a bit more tricky. Pretty much anything electrical, especially light emitting stuff, will produce heat, difference is LED's don't EMIT heat (radiant), so you can stand in front of them and not feel any warmth, nor defrost your headlamps this way. The heat is generated at the base junction, and can be pretty inefficient, as with most light emitters, 10-30% I heard at uni, but must be better now. This is a reasonable article about it: http://www.ledsmagazine.com/articles/2005/05/fact-or-fiction-leds-don-t-produce-heat.html HTH Quote Link to comment Share on other sites More sharing options...
need4speed Posted September 12, 2015 Share Posted September 12, 2015 That's pretty interesting Bowie. Just read that through. Still, I haven't heard of these LED headlights failing due to overheating. That doesn't mean to say it's impossible of course Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 12, 2015 Share Posted September 12, 2015 To add, say these were them (first google hit): http://www.ebay.com/itm/0547891-Evolution-Round-7-LED-Headlight-Black-97-14-Fit-For-JK-Jeep-Wrangler-TJ-/121550922014 40W high beam, so *IF* they are 30% efficient, then that's 27W of heat coming out the back of it, well out of the airflow. I presume they design the heatsinks to cope no matter, so leaving the bowls as-is would probably not cause a problem, BUT, I would still be hacking them about A halogen bulb on main beam is 60W, but only 3.5% efficient, so producing around 58W of heat. HOWEVER, mostly radiant, so it goes out your headlamp lens. So yes less heat, but a different type, requiring a different solution One big problem with LED lamps is going to be icing over in winter while driving(!) Do they have to have washers installed on factory vehicles because of this? Quote Link to comment Share on other sites More sharing options...
robertspark Posted September 12, 2015 Share Posted September 12, 2015 ... this could go way off topic... Phil to answer your question, the heat comes from the power the LED's use in operation... Those fittings are 30W full beam and 18W dipped beam... hence 30W is used to produce heat in one form or another. "heat" can be emitted from an object by radiant (best to think of it as light [but from the infra-red spectrum], this can travel through a vacuum and uses a very simple formula P=Area x emistivity x stefan boltzman constant (5.67x10-8) x object temperature in Kelvin ^4 [P=A e 5.67E-8 T^4]), is can also be conducted and it can be convected away. by trying to keep the LED cool (as they don't like heat, and actually self distruct... more heat... more current draw... then fail) there is very little radiant heat relative to the surroundings, conduction is what draws the heat away from the LED and then you need convetion (air or water flow over the object) to cool or keep it cool.. Rob Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 12, 2015 Share Posted September 12, 2015 Think it is all pretty much on topic so far Quote Link to comment Share on other sites More sharing options...
need4speed Posted September 12, 2015 Share Posted September 12, 2015 Thanks for the explanation guys. So the LEDs produce heat just in a different way. Therefore when I eventually get them I will make sure I have the bowls that are open at the back.. As you were.. Quote Link to comment Share on other sites More sharing options...
robertspark Posted September 12, 2015 Share Posted September 12, 2015 As Bowie69 said.... halogens (and all other forms of incandencent lamps) need to heat a fillament hence the heating of the fillement increases the fillament temperature to the point that the radiant proportion (equation above... temperature difference to surroundings to the power of 4 [in kelvin! (ie 273+temp in celcius]])... starts to matter more than the convective element... but if say the lamp is 100W halogen and 30W LED.... what in heat terms is the actual difference.... well they may be very similar.... given the halogen may actuall have a 70% radiant proportion (due to the hot fillament) and the remaining 30% is conductive then convective (some will be lost to the reflector and glass etc). But the LED has near zero radiant proportion... just conductive and convective... as it needs to keep cool. Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted September 12, 2015 Share Posted September 12, 2015 The factory fit Nolden LED headlamps on the run out adventure and autobiography models have no headlight washing systems. Quote Link to comment Share on other sites More sharing options...
robertspark Posted September 12, 2015 Share Posted September 12, 2015 One big problem with LED lamps is going to be icing over in winter while driving(!) Do they have to have washers installed on factory vehicles because of this? err... I dont think that is going to be a problem (and washers would not solve it as the water would be cold unless you continually squirted warm water at them).. the 18W on dip / 30W on high beam is still heat input that will heat the surface of the lamp (I may stick one on the bench wired up and let it stabalise temperature and take an infra-red thermometer reading if I can be ar"£%) Hence at 18/30 W it would need to dissipate this to the surroundings and it cannot (laws of physics) be the same temperature as the surroundings and still emit 30W or the surroundings would need to be an immense heat sink of infinate thermal conductance with no surface resistance (submerged in water would do it... but the water wouldn't be freezing then...[technical smart ar"£$ at work...]... hence the objects temperature will rise above the ambient temperature to the point where there is a heat balance and the amount being input is being extracted off the object at the same rate... in short ... they won't ice over... hat coat... I'll be off I had some soldering to do... :blink: :ph34r: Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted September 12, 2015 Share Posted September 12, 2015 Washers with de-icer obviously... With little heat radiated to the thin plastic lenses I still think it may be an issue. Will find out I guess Quote Link to comment Share on other sites More sharing options...
robertspark Posted September 12, 2015 Share Posted September 12, 2015 http://www.jk-forum.com/forums/jk-electrical-lighting-sound-systems-13/led-headlights-icy-snow-conditions-264395/ there is a truck-lite email posted here around the bottom (but the yanks do have snow!!) http://www.jkowners.com/forum/showthread.php?t=83292 or if you really want the answer.... https://www.youtube.com/watch?v=N3a7FbjHYAc https://www.youtube.com/watch?v=sP9gltzn72Y Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted September 13, 2015 Share Posted September 13, 2015 The heated element is a nice solution.....but our snow in the UK doesn't really stay nice Virgin white for long. After the application of salt and sprays it turns into a nasty brown slush which as I'm sure we've all experienced dries to a nice opaque film on conventional halogens due to the heat. So on the flip side if the LED lights aren't getting so hot and are caked with a dirty salty solution then it should hopefully wipe off rather than being scraped off! A lot of OE headlights are coming with LED hardware now so you have to assume that they will have been cold weather tested prior to approval?? Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 Re the heat. Issue and the headlamp bowls, is there anything to be said for the full bowls protecting the trucklites from the engine bay heat somewhat? I'm going out to fit them shortly and I don't think I will chop the bowls at this point, can always whip them out later to do it. Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted September 13, 2015 Share Posted September 13, 2015 I can't see engine heat soak being a concern. If the most common application for this style of light is on a jeep c-series which tend to have a large v8 or straight6 working in a greatly warmer climate then a draughty defender bay with our milder weather should be no problem. Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted September 13, 2015 Share Posted September 13, 2015 The video posted on page 1 was by a Swedish inhabitant....any issues with icing or snow? Quote Link to comment Share on other sites More sharing options...
tuko Posted September 13, 2015 Share Posted September 13, 2015 I quickly read through the comments about heat issues and if I may add my opinion as I've been running the same headlights for 2 years, stop worrying about it! I've never had an issue with heat what so ever, I have galvanized headlight bowls that are unmodified, the headlight wires are crammed directly behind the lamps and there is no signs of any heat damage of any sort with them. Winter driving is perfectly fine to, until it snows. Snow will stick to the lights just like it would do with any other front portion of the landy when it's driven in a snow storm. There's actually not enough heat build up within the lens housing to warm the lens enough so that the snow will melt. The above picture, This was taken after a short run (2km) to the grocery store in a snow storm. I've actually removed the headlights the past 2 winters so that I have proper illumination in front of the landy. It's a trade off for having these LED headlights, but it's well worth it in my eyes for the better light output and light spread. Todd. Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 All fitted. Some pics (Not in the dark yet). Quite pleased with them so far. (doing this made me note the state of the sidelight and indicators though - i think an LED set for these will be next!!) Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 Just been out for a quick spin. First impressions are that they are brighter, but they have a much more defined cut off on dip beam and that is about 2 car lengths (back to back) away from the front of the truck. Does that sound the same as those that also have them fitted, or is my alignment set too low? Just turned the disco (normal halogens) on to compare and on dipped beam, the beam seems to travel further from the front of the disco than the LEDs from the front of the 110. Quote Link to comment Share on other sites More sharing options...
Scotts90 Posted September 13, 2015 Share Posted September 13, 2015 When I get round to fitting mine I'll mark up the existing beam pattern on the inside of the shed door then adjust the new lights to suit. Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 Should've done that, but no convenient wall! I actually assumed they'd be set correctly in the same spot as the originals if I didn't move the bowls on setup. Quote Link to comment Share on other sites More sharing options...
tuko Posted September 13, 2015 Share Posted September 13, 2015 Should've done that, but no convenient wall! I actually assumed they'd be set correctly in the same spot as the originals if I didn't move the bowls on setup. They have to be adjusted. I found 2 full turns upwards with the LED's put it them near to the standard lamps. Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 Bugger. I thought they were a straight swap. Is that top screw two turns anti clockwise to move them upwards? Quote Link to comment Share on other sites More sharing options...
tuko Posted September 13, 2015 Share Posted September 13, 2015 Bugger. I thought they were a straight swap. Is that top screw two turns anti clockwise to move them upwards? Correct me if I'm wrong, but anti clockwise will screw the screw outwards making the light tip down. Clockwise will raise the light beam. Quote Link to comment Share on other sites More sharing options...
reb78 Posted September 13, 2015 Share Posted September 13, 2015 Correct me if I'm wrong, but anti clockwise will screw the screw outwards making the light tip down. Clockwise will raise the light beam. Yep. I think you are right Tuko. I watched your video again. Dipped beam is very similar on your video to what I experienced tonight. I'll try it again tomorrow and see how it is. I think it is the very definitive cut off of the light that seems strange on first use. Quote Link to comment Share on other sites More sharing options...
western Posted September 13, 2015 Share Posted September 13, 2015 Bugger. I thought they were a straight swap. Is that top screw two turns anti clockwise to move them upwards? the adjuster screws are normal right hand thread so screw in to raise the beam pattern. Quote Link to comment Share on other sites More sharing options...
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