Inexpensive H4 / 9003 / HB2 LED headlights ($32) - trying on the Prius & motorcycle

[Daox]

Thanks guys. I'll just do that then.

[deejaaa]

Originally Posted by Daox

.....I'm not sure why I'd need a ballast? These LEDs run straight 12V power coming off the battery. They shouldn't be seeing any voltage spikes.

it's not a ballast. it's this:
DC11-35V to 11-35V 10A Constant Current Constant Voltage Boost Converter Step-up Power Module. put in 12v and only 12v output. my alternator runs between 13.3-13.7v depending on it's needs.
http://www.dx.com/p/dc11-35v-to-11-3...3#.VVaAYJNtGQw
this one is adjustable. these LEDs are already overclocked, reason life is not as long as others with lower output.
ebay has some too:
http://www.ebay.com/sch/i.html?_odkw...Power&_sacat=0
just make sure to match amp/watt.

[Daox]

If they're made as an H4 replacement, wouldn't they be designed for 13-14V operation?

[deejaaa]

you're probably right:
The current–voltage characteristic of an LED is similar to other diodes, in that the current is dependent exponentially on the voltage. This means that a small change in voltage can cause a large change in current. If the applied voltage exceeds the LED's forward voltage drop by a small amount, the current rating may be exceeded by a large amount, potentially damaging or destroying the LED. The typical solution is to use constant-current power supplies to keep the current below the LED's maximum current rating. Since most common power sources (batteries, mains) are constant-voltage sources, most LED fixtures must include a power converter, at least a current-limiting resistor.

[Daox]

I got the bulbs the other day. They look very nicely built, but they definitely are not small! I got some pictures here.

I hope to get these installed on the Prius in the next day or two and I'll get pics with the headlights shining on the garage door at 10 or 20 feet away, and also a shot with them shining down a road or my driveway or something. I'll do this with a halogen in one side and the LED in the other for comparison.

Installing this on the motorcycle is going to be a bit more work. I'm pretty sure I'm going to have to cut out the back side of the bucket to make it fit.

[NeilBlanchard]

Ahh - I like their design. The flanged piece can get installed easily, with room for the wire retainer clips - and then the bulb and heatsink slides in (and latches?).

[Daox]

Yep, the bulb part slides in and its got a 1/8 turn or so and it locks in.

[freebeard]

I'm running Cree-alike LEDs in Hella H-4s, and I don't like the beam pattern, it's round while the halogens were completely flat on the top. I'm going to try aluminum tape across the top of the lens to flatten the pattern. Right now their canted down so the high and low beam are about the same.

I like the color temperature a lot; but they don't throw light as far down the road, possibly because of the way their aimed.

Looking forward to those pics. I paid $55 for the pair.

[Daox]

I installed one of the LED bulbs (passenger side) today. Install went pretty well. Here are the pics:

Here is where we start.




Lets get the intake pipe out of the way, and now we have access to the headlight bulb.




I pulled the old bulb out and shot a comparison picture.




I installed the reflector and bulb base.




Then, I had to do something about the connector. It was sticking straight up, and the plastic housing was overhanging it. So, I took it apart and rotated it. A half dozen screws on the back hold it together.






Here are some of the guts. Looks like a couple inductors, a capacitor and probably some other stuff.




Here it is all buttoned up. There wasn't a ton of extra room to get the new bulb in there, but it did fit without too much hassle. The other side will probably be a bit more tricky as the fuse / relay box is right behind the headlight.




Oh yeah, don't forget bulb grease (though I've never seen corroded headlight terminals).

[Daox]

And here are a few pictures I got last night. The beam pattern isn't perfect, but its really not bad either IMO.

Driving with it, it seems a little brighter than the halogen. Obviously the color temperature is different. The night pictures were very difficult to get anything that looked anywhere close to not blurry.

Here we have the lights against my garage. This is probably about 20' away from it. These are the low beams. I forgot to get a picture of the highbeams.




Low beams shining down my driveway. In reality, the lights are not as bright as what the picture shows. It also makes it seem like the halogens are brighter, that really isn't the case. They're fairly comparable with the LED being a big brighter.




High beams shining down my driveway. In reality, the lights are not as bright as what the picture shows.