LED replacement bulbs

[Knavish]

Do any of you have experience with LED replacement bulbs for cars? I need to replace my licence plate bulbs to pass inspection (should have noticed that before going in...DOH!)

Superbrightleds has lots of options, and I've used them in the past for non-car LEDs, but they seem really expensive, for example:
SuperBrightLEDs 2x$5.95
vs.
Ebay $1.15

 

[slayernine]

If I didn't have a brand new car I would be very tempted to try this. I was going to do it to my 99' Accord but I went and sold it.

There must be a guide to doing this on instructables.

 

[Mark R]

They're basically all the same - they all use cheap Chinese LEDs, but some LEDs are brighter than others.

I've had some for a couple of months and they've been OK. I replaced the parking lights on my IS250 with them, when I had to replace a bulb. I'm hoping they'll last longer than the regular filament bulbs (as it's a real PITA to change the bulbs - have to take out the whole intake, including air box).

There are a number if sizes of LED offered on this type of bulb:
The most common are 5050 SMD (5mm square with a round center) and 3828 (3.8 x 2.8 mm rectangular), but you can get smaller, even weaker ones. The weakest are the domes ones that look like regular LEDs. These are worthless.

The 5050 are a lot brighter than the smaller sizes, mainly because they usually contain 3 dice.

I would expect a 5 LED 5050 bulb to be about as bright as stock; I have 9 LED 5050 bulbs for my park lights and they are a lot brighter than stock.

Also remember that LED bulbs only work one way round, so you may need to turn them round if they don't light up.

Finally, note that LED replacement bulbs may be a lot longer than the stock bulb and therefore might not fit. Check the length of the bulb carefully.

 

[phucheneh]

I don't know if I'd trust Chinese LED's and the accompanying circuitry to even last longer than a regular bulb.

Also, you may end up with fast-blinking lights or a warning light/message (if your car does that for bulbs). I don't believe those LED 'bulbs' are going to be anywhere near the same resistance as the standard ones.

 

[Gillbot]

They are cheap enough, try it.

 

[KIAman]

I converted all my interior bulbs to cheap white eBay LEDs in my car for 3 years. It was over 16 bulbs including the trunk. Never had an issue with them at all. I think the entire kit cost me around 20 bux.

 

[Knavish]

I don't know if I'd trust Chinese LED's and the accompanying circuitry to even last longer than a regular bulb.

Also, you may end up with fast-blinking lights or a warning light/message (if your car does that for bulbs). I don't believe those LED 'bulbs' are going to be anywhere near the same resistance as the standard ones.

I've heard about the fast blinking / warning problems some people have with certain lights. I guess this is because they are using them on a turn signal or other monitored light bulb. The LED has much lower resistance than the original lightbulb, and they may be relying on the reisistance to change the blinking speed. (i.e. RC time constant) Actually, I wouldn't be surprised if my car does this since it's not too new. This shouldn't be a problem for me because I am just replacing licence plate bulbs (at this point).

A load resistor actually solves this problem, but it also consumes power / generates heat just like the original bulb. Some places even sell load resistors specifically for car led lightbulbs.

 

[Knavish]

ok I should have checked Amazon first. They have loads of LED bulbs that supposedly fit the 194 socket. They're close to ebay prices and hopefully not shipping directly from China with 2-week slow-boat shipping. I'll try a couple of these & let you know what I think.

 

[chin311]

I've replaced my license plate bulbs, courtesy door lights and reverse lights with LEDs.

I can try to grab a night shot but this is from when I installed the reverse bulbs, a comparison although in daylight hours. Much brighter and whiter at night.

 

[phucheneh]

LED's have a higher resistance. Sort of.

LED's don't really have a resistance, as a diode is not really a load. I'm no electrical engineer, so it's not something I know much about. The 'light emitting' part has to consume some voltage, but as it's actual light energy being produced and not just heat that is visible because of a glowing filament (I guess that would be electricity>heat>light), it's...different. That's about as good as I can do.

But as far as those 'LED bulbs'- they're not a bulb, but are their own circuit with LED's included, and they must have resistors in the assembly. The resistance has to be higher than a standard bulb, or they would not be more energy-efficient. Voltage is a constant (when comparing LED assemblies and incandescent bulbs, that is), so if the resistance was less, it would have more current flow and therefore a higher overall wattage. Ohm's law and whatnot.

IIRC, LED's typically only use a couple volts. So the rest of your ~12-14v input must be burned off as heat by the resistors.

The lights blink differently because the total resistance of the circuit has changed. Same as if a light went out- the bulbs have to be in parallel to get a full 12v, and parallel circuits decrease resistance. Put an open in one leg, and the resistance goes up.

On older cars, this affected the frequency (possible bad terminology there) of the 'flasher' unit, which is effectively another resistor. As it heats up, contacts open, then it cools down and they close...repeat ad infinitum. Until it goes bad, at least.

On newer cars, a BCM drives the lights with a transistor. I believe the fast blink is on purpose to let you know that a light is out, but it happens for essentially the same reason- the resistance of the circuit goes up (which the BCM sees).

I think that's all right. Someone else can feel free to correct anything I got wrong.

 

[rsutoratosu]

I get mine from http://www.v-leds.com/, most of them have measurements so you can match your socket. Yes some 194 are longer than others, etc.. may or may not fit. Plus vleds usually have coupon for 5 or 10 % off, down side is they're mad expensive but they seem to have the brightest ones i seen