Smart Car of America Forum banner

LED Headlight Conversion

35K views 82 replies 30 participants last post by  AlMar 
#1 · (Edited)
After 7 months of somewhat constant use, my right side HID has dimmed just a tad. I'm fairly sure my left side will soon follow suit. Eventually I'll have to replace my HIDs (I think they'll last easily another 7 months) but I'm thinking this time I want to try a new technology.

For a long while I've been amazed at Audi's all LED headlamps in the R8 and A8 (and A6 I think) and wonder why the aftermarket hasn't gone nuts with them yet. LEDs are cheaper than HIDs and they last twice as long (almost the life of the vehicle) while being easier to install and providing a more controlled output of light than any bulb.

So after an hour of searching, I've found H7 LED "bulbs" that are a direct replacement for the low and high beams. They're dramatically cheaper than HIDs and create light equal to 6000k!

BMW Mercedes H7 18 SMD LED Bulbs Foglights Fog Daytime Running Lights

68-SMD H7 LED Bulbs | H7 DRL Replacement Bulbs | H7 LED Fog Light Bulb

What do y'all think? I'll run my HIDs (thanks Uptown Dog! They're marvelous) until they're almost completely dimmed out then switch to LED...By that time they'll probably be even cheaper!!! :D
 
See less See more
#2 ·
Those bulbs are not appropriate for use in headlamps (you'll even note they mention "daytime running lamps" and "fog lamps"). They won't generate nearly enough light nor will they work properly with your headlamps' optics, which are designed to focus and project light from the very specific location of the H7 bulb's filament.

LED headlamps are very specialised units that must be designed from the start to utilise the LED light sources, properly dissipate the heat they generate, and produce an appropriate beam pattern.

Unlike HID capsules, which can be fitted in halogen applications in such a way that the arc closely approximates the position of the original filament (though even then the results are not as effective as a true HID headlamp), LEDs cannot be retrofitted in the same fashion.
 
#4 ·
I believe if you check into the pricing on the LED headlights in use on the Audis, you will find that, far from being cheaper than your HIDs, their price is prohibitive, for most of we 47 percenters.

And, as Padawan pointed out, the H7 LEDs aren't bright enough, and the Audi fixtures are designed specifically for the use of those very pricey LED headlights.

Sad but true. I've investigated it myself and came away convinced my pockets aren't deep enough to consider any headlight LED option. At the present time. Maybe something practical will arise down the road.
 
#8 ·
Well if they have direct replacement LED DRLs and fog lamps driving lights can't be too far off...

I'll continue to look, Audi has been using them for a few years and it's weird the aftermarket hasn't made their own yet!
 
#10 ·
LEDs have to be shaped by some type of lens. I think you could well home-brew a set, but I don't think it would be cheap. You'd have to have quite a number of them for high and low beams and they would all have to be aimed precisely. @ $5-6 a piece for the LEDs, not including the boards to drive them, it won't be near as cheep as the HIDs you are running. LEDs have come a long way over the last 6-7 years so it may happen eventually. You can check out Candle Power Forums. Home-brew you a flashlight, or a bike light to get some idea of what it would take!
 
#11 · (Edited)
from what you all are saying about the number and intensity of the LEDs that would be required for headlights, it sounds doubtful there would be less current draw with LEDs too (???)

Lower current use for a given light level is one of the practical virtues of LEDs in applications like bike lights, helmet/climbing lights, flash lights. Your batteries last immensely longer with LEDs in bike lights and climbing lights than with standard filaments.

I've assumed this current draw advantage is also true of the smart's LED daytime running lights, assuming the same light level as regular DRLs. Anyone know if this is true?
 
#13 ·
Google and (religious figure forbid) Bing aren't helping too much, most of my results are for LED strips and other use LEDs...there's gotta be something aftermarket by now...

I love my HIDs and all, but the idea of a nearly forever lasting lightbulb is really attractive! That and I have way too many wires hanging around up front :D
 
#20 ·
22 LEDs for each light. Each is probably drawing between 350 and 500 mA -- so you can do the math on the total current draw. I notice they are using some lenses to focus the light as well. you could do the dame with some optics and individually direting eash LED to get the shape you want, but it would be a pretty big challenge!
 
#21 ·
More research...
You'd need at least 1000 lumens just to make the LEDs equal to halogens. Any direct replacement LED bulb will be putting out around 400 lumens max...not only is that half the legal requirement, but it'll be like attaching candles to your car and trying to drive at night!

A CREE LED setup will do the trick, but since they're usually encased in expensive flashlights you'll need some Homebrewing to get it to work!

Drat!
 
#32 · (Edited)
Lumens are merely a measure of the light-intensity. You could have a really tiny spot with high intensity. The problem is you need a large are with a relatively high intensity. and that is harder to come by.

Also, the longevity is proportional to how hard they are driven (or over-driven). If you are only driving them around 350 mA, they should last a good long time.
 
#26 ·
There's absolutely nothing wrong with the OE halogens. I was very pleased with them. I got the HIDs because I liked the idea of more focused light, longer life, better durability, and a light blue glow that matches my car. (that and you can't beat free thanks to Uptown Dog!)

When I saw my slightly dimmed passenger side HID (thought it was just normal wear) I thought "hmmm...is there anything better than HIDs?" and then that's when LEDs came into mind.

I love trying out new ideas even if in theory they shouldn't work. It's the only reason I have an 8-Ball shifter when all smart vendors don't even sell them! But of course in this case, looks like it would be a waste of time...although I think I discovered LED/HID heaven as that site lists all kinds of bulbs!
 
#27 ·
LED technology for high wattage bulbs is still maturing. Yes, they do generate lots of heat that has to be delt with, as indicated in a previous post. LED bulbs available as aftermarket, at the present, are only really meant for show purposes where a car is on display and they want the headlights on. Since LEDs draw very few amps, they can be run off a battery for quite a long time while on display w/o dangerously discharging the battery. Besides, don't believe all the hype about how long they will last. Many folks are experiencing early and frequent failure of LED high wattage (125 equiv.med. base screw in bulb) spot and flood bulbs. Just read the reviews. I have been using SilverStar and now SilverStar Ultra bulbs in the headlights of my four cars, a scoot and a cycle for several years. Not one failure and the lighting is superior to stock bulbs. Two bulbs in the scoot and one in the cycle, subjected to pretty rough service.
 
#28 ·
RE: SilverStar Ultra headlamps. Yours is the only testimony I've heard regarding satisfactory longevity of these bulbs. From the bulb's packaging itself, to salespeople in auto parts stores, to other users on this forum, the consensus previously was that their service life was significantly shorter than some less expensive, lower output headlight bulbs. Which is why I've never tried them. Interesting that you've had a different experience. Duly noted. :)
 
#29 ·
Silverstars and Ultra SS sold here are merely blue coated bulbs to cast a whiter light. They actually have less light output ( lumens ) than a stock bulb . Even if someone had no knowledge of that , there's disclaimers on every package of SS . There is a version sold overseas that is better but not the SS you find at Pep boys ect .
 
#33 · (Edited)
Blue? Really? No blue coating unless it is very faint. The metallurgy of the filament is different to allow it to burn brighter as is the gas in the envelope so the filament doesn't burn out. Not certain where you got your info but it isn't true. Can't believe everything you read on the Net!

Yes, I've read the same about SilverStars but it isn't all negative. There are lists of folks who have had the same experience as I. My SilverStars have all Ben manufactured in Germany. Some of them were made in the U.S. and did seem to have problems. My oldes, original set - still in continuous use in the scoot - came from the U.K. And are several years old. All the others are the newer Ultra versions except the sealed beam SilverStars in my 1977 230 Benz. Like I said, not one failure and I have DRLs on a couple of my cars. Oh, forgot to mention that my son has used a few sets in different cars - all without failures.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top