LED Turn signal bulbs

Clearly, the LED bulbs seen in the video that Prius 06 used are not as effective or visible as incandescent bulbs. Those have a viewing angle of only 35 degrees. At 120 and 130 angles of beam pattern that the two I've listed (and Prius 06 indicated as "more expensive" ones, I'd imagine the reflectors will see at least SOME action of amber light.

I'm definitely going to go ahead and make the purchase - the questions I've asked needs to be answered, however. HP3 or LX3?

 

XHP3 is a smd LED and they are not that reliable compare to XLX3. The XLX3 are under power per specs and life expectancy will be better than XHP3. The maximum current 3W Luxeon LED can run is 1.4A, typical forward voltage 2.95V, typical luminous flux 110 lumens. Also, they can't run the XLX3 to maximm current due to its junction temperature or heatsinking the LED. Hope this helps.

 

Mine are the 15-LED blub with a 90 degree viewing angle.
Living in Canada, I thought I'd try these first. I'm happy with them on the Prius. I have the really expensive ones (25/bulb) for my other car...however it's currently being built and I have yet to put the flasher in or the lights.

In the video the car was facing the sun. I will try to take another day shot where the car isn't being hit with direct daylight for you guys.
However, you can always purchase the WLED-WHP15-T bulbs, as I'm sure they'd be alot brighter.

 

So pretty much the LX3 are the best bet. Thanks everyone! Will return with installation pics/video.

 

Looking forward to it, then I know if it's worth it for me to upgrade to high priced bulbs or keep the ones I've got.
Just sucks being in Canada and trying to order them from the US.

 

Ok, so it only took me a month but I took a video today comparing the stock bulb to the led.
Anyone else done the led conversion yet?

 

I had originally used the leds shown in this video but found in the day time they were not bright enough. I found some others that I will post a picture of that work better.

 

Almost as bright. Leds on the left, stock on the right.

 

those are good enough.

what type name and where did you get them

 

Hi All,

Is there a thread, or any recomendations on LED running lights ?

 

Thanks for the suggestion, Tideland. The unfortunate problem is that I lack the material as well as the fabricating tools to create such modifications. <:0) Plus the housing is quite small, which would imply delicate construction and assembly, which requires more precise construction.

There are plenty of cars here @ socal that seldom use turn signals - myself included. I think I'll be all right for now during daytime. 10+ years of accident-free driving record with seldom use of blinkers! *crosses fingers*

The day a 270-degree LEDs come out, I'll replace these. Haha :0)

 

I found the 15 LED 7440's to be good replacements due to the design which has 9 LED's at the end of the bulb and 6 that shoot out perpendicular to that...all with 90 degree angles. this combination *almost* gives you the 270 degree angle that you were looking for. ...and they're much cheaper at $7/ea vs. $25/ea. I used them in my 2010 and they are much more visible than the ones in your video.


15-LED 16mm Wedge Base bulb
12VDC 16mm Single(7440) or Dual(7443) Intensity wedge base replacement bulb
15-LED Design has 9 LEDs aiming out the end and 6 radially mounted LEDs aiming 90 degrees from the base
Select Base type & LED Color
$ 6.99

 

I just bought a used 2006 Prius and am fairly experienced with LED lighting design both for home and bicycling use. thought I'd add a little to the discussion of LED lighting on the Prius as I have started to turn my thoughts on how to upgrade the various incandescent bulbs in the Prius. The following is a long and rambling screed, be warned.

Regarding the SuperBrightLED bulbs being discussed (xHP3 and xLX3):
The xHP3 does not list a constant current driver as part of the design. This should immediately disqualify it for use, as your bulb current will be impacted by fluctuations due to changes in temperature, battery/generator voltage, part tolerance etc. This will impact both performance and lifetime.

Additionally, the claimed performance for the HP3 bulb is highly suspect. If the draw is 96mA at 12V and 53 lumens output this represents nearly 47 lumens per watt which is well beyond the current capability of amber LED technology. The best amber LEDs available are in the 30 lumens per watt range. The 23 lumens per watt reported for the xLX3 is much more believable.

Regarding LED lighting for automotive applications in general:

Beyond the issues with reflector design and cost, the main issue holding back LED replacement for incandescent bulbs in the Prius (and most lighting situations) is heat. LED performance and lifetime are both negatively impacted by heat. Thus the hallmark of a properly designed, high performance, high output LED lighting product is the size and performance of the heat sink. The small incandescent bulbs and their housings in use in the Prius (and cars in general) do not lend themselves to incorporating adequately sized heat sinks with adequate airflow for high output LEDs. If you replace a 15W tail light with an LED of equal output, the LED bulb will still dissipate ~3W of heat. While the incandescent will perform better hot, the LED will most decidedly not.

Automotive housings being designed for harsh environments there is no airflow and being designed for incandescents there is no significant heat path out of the housing. Without airflow or a heatpath, the LED and its attached inadequate heat sink are literally baking themselves in an airtight oven.

As the termal pad temperature of an amber Philips Rebel LED (significantly better than the Luxeons used in the SuperBrightLED bulbs) goes from ambient to 40C, the light output will drop to 75%. At 60C output drops to 55%. In a sealed environment the performance of the heat sink drops off considerably and the pad temperature of a high power LED can be expected to easily hit 60C and reduce the light output by half.

Additionally, running these LEDs hot will reduce their lifetime. Lifetime is often defined as the time to 70% luminuous flux, meaning that even at turn on the LED will get dimmer with age. Thus an old LED bulb will get dimmer, and an old hot LED bulb will get even dimmer even faster. Note that SuperBrightLEDs lists lifetimes for their high power bulbs of 20,000 hours when the manufacturers of the LED chips list 50,000 hours typically.

There are no respectably engineered LED bulb replacements that I am aware of for automotive applications. A proper retrofit solution would have to consider replacement of the stock plastic bulb holders/plug and associated wiring with a design that provided a heat path out of the sealed housing. This could be done by making the plug out of aluminum with suitable fins rather than plastic.

Will the discussed LED bulb replacements work? Of course they do.

Do they provide the lifetime and output of a proper purpose-built LED fixture? No.

Do they provide the same DOT approved level of safety as incandescent signal bulbs in all lighting conditions? In my opinion, no.

Do LED replacement bulbs have a place in your Prius? Certainly, but I would hesitate using them for any safety critical application such as turn or hazard flashers. While the low duty cycle of these applications can be expected to improve the thermal concerns somewhat my opinion is that the viewing angle and outputs are not equivalent to incandescent for the discussed LED bulbs.

Using a multi-LED emitter as suggested by antiflash is not only a better idea for viewing angle, the use of lower peak-power LEDs spread over a larger area should result in a better thermal pad temperature for the LEDs as well. The reduced heat load will increase lifetime, light output, and loss of luminuous flux with use and age.

With all that said, I expect to replace some of the incandescent bulbs in my Prius with LED bulbs of some type shortly. Will advise.

-Jon

 

Thanks for the very informative post, Jon. I have pulled my LX3s out re-installed the incandescent bulbs back in. Visibility is a better thing than LEDs at this time. I suppose my LX3s will be on eBay soon.

 

I'd say that is a safer choice. The lifetime for these LED replacements may very well be higher than an incandescent even with increased thermal load. My experience has been that most automotive bulbs last long enough, as I can count on one hand the number of bulbs (non headlight) I have replaced in some 250,000+ miles of driving.

An additional consideration is that the power savings are fairly minimal for turn and hazard bulbs. If you use them 5% of the time and they are 50% duty cycled, the power used by a 15W incandescent is only 375mW on average. For a non-hybrid car the point is essentially moot since the alternator is spinning no matter what but in the alternator-free Prius there may be an aggregate benefit for all bulbs.

As a back of the envelope estimate, replacement of 12 incandescent bulbs (15W) with LEDs (3W), assuming a mix of bulb applications (markers, turn, tail, license, etc) that yields avg 66% duty cycle gives a potential savings of 96W continuous. If we travel at 60mph and the car requires 250Wh per mile at that speed, the instantaneous motive power is 15kW and the LED replacements would yield a 0.6% reduction in system operating power at night with lights on. Small, but potentially measurable. The added weight of the LED bulbs and heat sinks would partially offset these gains and in practical terms the impact would be tough to see.