Converting exterior lights to LED

[scottydl]

LED replacement bulbs for 12volt light fixtures will never drain your battery set ups and will never burn out. they are a little expensive, but twice as bright, each bulb costs about 19 bucks.      http://www.ledlight.com/detail.aspx?ID=128

This comment from another thread prompted me to wonder if anyone here has converted their exterior coach lights to LED's.  I'm thinking of taillights, brake lights, roof clearance lights, etc.  I've seen some plug-n-play LED bulbs (that supposedly plug right in to the existing sockets), or square brake light fixtures that are supposed to easily replace the factory ones containing the standard filament bulbs.  I don't care so much about power drain, as I do about visibility and looks.  Obviously LED's are much brighter at night and in rainy/foggy conditions.  Most semi's I've seen have LED's on their trailers now, and I'm guessing newer MH's are coming equipped with them also.

 

[John From Detroit]

I have done some of them. Will do more as then need arises

 

[Hfx_Cdn]

I think the intention is for LEDs to be used for breaking lights on your toad.  That's where you need to conserve the power in a battery that is not getting charged.

 

[John From Detroit]

I use a LED set on the back of the coach,  Towed lights are standard,  I don't worry about the towed's battery as it's always fully charged when I disconnect.

US-Gear Unified Brake Declerator includes a 40 amp towed charge line,  Works great

NOw... If I'm not towing.. If it's just sitting there... Battery can barley survive over night just parasitic loads will kill it.

 

[King]

I havn't been able to find power ratings on the LED replacement assemblys for the conventional bulbs.  I would think that if they could talk about reduced power for their assemblies they would.  It has been a few years since I have used LEDs, but they used to use about 20mA each, and had to use a dropping resistor in series to get the voltage down.  Does anybody have any recent info?
Art

 

[pollittax]

we did eight on our trailer, they matched at the mounting holes and a little caulk we were done. i think they were made by blazer, frow walmart. about 7.50 a unit. very very bright at night, looked great. one thing to be noted about led replacements, is they very long life they last. bumps and bangs of of the road can break a normal filament bulb "1157" type bulb. leds withstand lots of abuse, and still just light. BUT if a led light does fail you have to replace the whole assembly, not just a .50 bulb. that being said, i love the way they look on our trailer!! besides over time marker lens covers will fade, so why not upgrade?

 

[regularguy]

I havn't been able to find power ratings on the LED replacement assembly's for the conventional bulbs.  I would think that if they could talk about reduced power for their assemblies they would.  It has been a few years since I have used LEDs, but they used to use about 20mA each, and had to use a dropping resistor in series to get the voltage down.  Does anybody have any recent info?
Art

Quality LED "replacement" lamps are 90% efficient v.s. incandescent lamps 30% efficient, considering usable light  v.s. consumed energy. Example: 100watts (input) / 30 watts (output) incandescent (1500 lumen). While 100 watt (input) / 90 watt (output) LED (4500 lumen).
Incandescent lights use 70% of consumed energy producing heat. LED lights use 10% of consumed energy producing heat.
Excluding initial cost to replace incandescent with LED, the LED will certainly consume less energy per lumen. Lumen is ALL IMPORTANT when considering replacement lamps.The light that you see with the naked eye is far greater with LED because LED light has a narrow output in the spectrum of light, while incandescent is very broad and most of the light produced cannot be seen by the naked eye. Most quality LED's have a 100,000 hour life expectancy (which means that the average life [of a given # of lights] is 1/2 will fail at 50,000 hours and 1/2 will fail at 150,000 hours. Incandescent lamps have a life expectancy of 1200 - 2500 hours. Note: "double life" incandescent means that the manufacturer used a filament capable of double the watts, but uses only half its capability. For the consumer, that means the efficiency of the bulb is lower because it takes much more energy to produce the same amount of lumens.
I know it is a long answer to a couple of relatively simple questions, but LED's are a wonderful thing. Just make sure to purchase from a reputable source!!!
Bottom line: if you really want more light output for the same energy AND you plan on keeping the vehicle, then LED IS the way to go.

 

[rbell]

I installed LED's on the rear of my last travel trailer. I'd had problems with water getting in them and corrosion. They also installed the original lights so low I was concerned people couldn't see them easily. I put the LED's about 1 1/2' higher. They came from Northern Tool & were sealed & soldered together. I figured the replacement bulbs would still have the corrosion issues.
The OE lights they use aren't very good quality.

 

[scottydl]

John it sounds like you may be the only person who's done an LED upgrade on your MH (vs. a toad or trailer).  What product did you use and what exterior lights have you upgraded?

 

[King]

Regularguy,  While everything you say is true, you still havn't answered my question.  When the diode assembly is lit, what is the current draw at 12 volts.  The voltage drop across a diode is usually between 0.7 v and 1.5 v.  In order to limit current at 12 v, there has to be a resistor in series with the diode, or maybe a switched power supply.  If it is a resistor, then the power lost in the resistor would be 10 times the power used by the diode.
Art

 

[John From Detroit]

John it sounds like you may be the only person who's done an LED upgrade on your MH (vs. a toad or trailer).  What product did you use and what exterior lights have you upgraded?

Well, I was convinced to change those tail lights by good old BOB, you know BOB, he's a Burnned Out Bulb

The 2nd time I had to replace a BOB brake/turn/tail light I switched them both to LED's  LED's last a long, long, time.

 

[Karl]

Art,
A typical LED rated at 30mA has a forward voltage drop of about 3.8 volts at rated current. Subtract this from the power source (12.6VDC for a typical auto or rv battery) and you need to limit the current to 30mA @ 8.8VDC. Substituting this into Ohm's Law I=E/R, we can see that the required resistor will be 8.8/.03=293, or approx. 300 ohms. Figuring worst case with the LED totally shorted, the maximum current drawn would be I=12.6/300 or 42mA. which calculates out to about 1/2 watt. With the LED functioning properly (not shorted), the 30mA drawn at 12.6 comes out to about 1/3 watt. Not very much in either case.

 

[Karl]

"Long life" or "extended life" automotive-type incandescent bulbs use a special filament and filler gas. This combination causes a re-deposition onto the filament of the particles of filament normally boiled away and deposited on the inside of the glass bulb - the blackening you see. The wattage and lumen output remains unchanged.

 

[regularguy]

Regularguy,  While everything you say is true, you still havn't answered my question.  When the diode assembly is lit, what is the current draw at 12 volts.  The voltage drop across a diode is usually between 0.7 v and 1.5 v.  In order to limit current at 12 v, there has to be a resistor in series with the diode, or maybe a switched power supply.  If it is a resistor, then the power lost in the resistor would be 10 times the power used by the diode.
Art

You could take the info and calculate/estimate but here are some links with ratings.
http://www.powerlineleds.com/led_power_consumption.asp
http://www.superbrightleds.com/specs/H3_11-WHP.htm
http://www.superbrightleds.com/specs/115x-x12x19.htm
http://www.bulbs.com/eSpec.aspx?ID=13557&Ref=Miniature%2c+Automotive%2c+%26+RV&RefId=25&Ref2=Light+Bulbs

 

[regularguy]

This is what I meant about "extended life" bulbs (incandescent): Example......
A 100 watt lamp produces 1730 lumens and has an average rated life of 750 hours. It is designed for 130volts (usually using a larger filament).
Now let's say we operate the lamp using 120volts. The percent disign voltage applied is: 100% (120/130) = 92.3%. According to the formula, watts comsumed are 87.8% or 87.8 watts. Lumens produced are 76.1% or 1318 lumens, and rated life is 283% or 2123 hours.
It is easy to see in the above example that although an extended life bulb will save money considering replacement cost, it will cost more in actual use because more bulbs are needed to produce the same lumens. Lumen is 76% or 24% less, while watt savings is only 12.2

 

[Just Lou]

Just an observation...   :  : ---- not trying to be critical.... ;D ;D

Why do some threads (started with simple questions like... What time is it? ) just naturally evolve into discussions of how the watch is constructed   ??? ???

Scotty, I have replaced several of my marker lights with LED assemblys that I purchased from Lowe's.  So far they are working fine.  I haven't tried lights like the tail/stop lights yet, but the mention, here, of "toad" lights has caught my interest.

I currently use the extra bulb in the toad tail light housing method so need to find something that will work with that implementation.    lou

 

[Tom]

We've historically called it 'thread drift' Lou, which is exactly what you and I are engaging in right now  ;D

 

[regularguy]

This is a site I have used in the past for my security system. I have a lot of infrared for night viewing. They have some good info
http://www.bgmicro.com/index.asp?PageAction=VIEWCATS&Category=115&Page=1

 

[scottydl]

Scotty, I have replaced several of my marker lights with LED assemblys that I purchased from Lowe's.  So far they are working fine.  I haven't tried lights like the tail/stop lights yet, but the mention, here, of "toad" lights has caught my interest.

I currently use the extra bulb in the toad tail light housing method so need to find something that will work with that implementation.    lou

Thanks lou.  I was beginning to fear my original question would never get answered, amidst a bunch of lighting math problems (barely related to my original post). 

 

[Mudd]

I,ve changed several tail-stop lights to LED and never had a problem with them , not on cars,trucks or rv's. Just make sure you reseal around the tail light's on rv's to keep any water out.
                                                Mudd