What gauge wire for 12v/100w car bulb?

[-Virgil-]

Using skinny wire allows you to trade off lamp intensity vs. lamp lifetime. The brightness varies by voltage^3.5 but the life varies by voltage^(-14) so a 5% drop in voltage will double your [incand.] lifetime with a 17% drop in brightness.

1. Your exponents are a little off. Lifespan is -13 and intensity (not "brightness") is 3.4.

2. It looks as if you are making the common error of failing to account for the extremely large effect of filament luminance on beam performance. As voltage drops, luminance drops off very steeply and beam performance nosedives along with it. As voltage increases, luminance and beam performance rise very steeply. It is inaccurate and misleading to leave out this factor and refer only to the percentage intensity loss or gain with voltage change. 1000 lumens with low filament luminance gives much poorer seeing performance at night than 1000 lumens with high filament luminance, and there is substantial crossover as well; 700 high-luminance lumens can give better seeing performance than 1000 low-luminance lumens.

 

[-Virgil-]

Re: Grounding points

Couldn't get any real numbers but it seems substandard lighting is the norm.

Very much so, in North America. Aim is almost never checked (and when it is, it usually isn't checked correctly or adjusted to a tight enough tolerance specification to do any good), headlamp lenses are often left in a state of unroadworthy degradation, and long-life bulbs with low luminance and low output are favored for their warranty-friendliness.

"Vehicles equipped with auxiliary lamps, a spotting light or any other lights used for lighting or clearance should not emit a beam with an intensity more than 300 candle power.

Text like this is found in some state vehicle codes. It is very old text, hashed up and rephrased over the years so that it is not applicable to any lighting device, original or aftermarket, actually available. Some state codes also forbid headlight bulbs emitting more than 32cp, which is truly ancient text, pre-1940, and laughable because 32cp is the output of a common turn signal bulb these days; if this provision and others like it were enforced, no vehicle, even a brand-new one, would be in compliance. The "300 candle power" thing is sometimes found in more sensible, enforceable form, "auxiliary lamps shall not emit more than 300 candlepower above horizontal" for example. Which is still imperfect, but is a great deal more realistic.

Federal Lighting Specifications
Upper beams shall range from 20,000 to 75,000 candela in intensity for each lamp. The lower beam will range from 15,000 to 20,000 candela in intensity for each lamp. These restrictions apply to Type 2 or 2A light classifications. The Type 1 or 1A limitations for lighting stipulates an upper beam that will range from 18,000 to 60,000 candela intensity for each lamp.

Don't know where you found this, but it's kind of hashed up as well. The "type 2 or 2A/type 1 or 1A" thing is ancient and the whole thing is not applicable to this conversation because it does not cover auxiliary lamps (which are not Federally regulated).

 

[Alaric Darconville]

2. It looks as if you are making the common error of failing to account for the extremely large effect of filament luminance on beam performance. As voltage drops, luminance drops off very steeply and beam performance nosedives along with it. As voltage increases, luminance and beam performance rise very steeply. It is inaccurate and misleading to leave out this factor and refer only to the percentage intensity loss or gain with voltage change. 1000 lumens with low filament luminance gives much poorer seeing performance at night than 1000 lumens with high filament luminance, and there is substantial crossover as well; 700 high-luminance lumens can give better seeing performance than 1000 low-luminance lumens.

In other words, suggesting someone attempt to reduce the intensity by reducing the voltage (through the use of inadequate wiring, no less) is simply ridiculous, especially when your math is off. I don't need to be a linguistics professor to know that! (Now I'm reminded of those people that lead decidedly non-Cartesian existences.)

 

[guiri]

Well, here's the thing. Last time I drove my Volvo with the good lights was around 93 so I could be very wrong. My eye sight is worse and all that.
Now, this doesn't change the fact that I'm not happy with the output of my Excursion lights, but like I said, it COULD be me.

As for lights not being aimed very well here in the US, I've had that opinion for years (no offense to anyone) because I'm particularly bothered by high beams and I've learned to see (and yes, I have been wrong) if someone's got their high beams on or not. Sometimes looking at them, I'm not sure but they still blind me and I think it might be that they are simply aimed too high.
Not sure if they check aim here when you get your vehicle inspected but I have never seen the aiming/checking devices they have in Sweden so my guess would be no. They're picky with stuff like that over there and frankly, for a good reason.

Also, lots of people here drive tall vehicles like trucks and so the light tends to be higher up.

As for my auxiliary lights, I only use them on country roads anyway. I'm good on highways.

Also, if anyone's interested, I could also try to take some shots of my highs with and without the extra lights.

 

[xul]

1. Your exponents are a little off. Lifespan is -13 and intensity (not "brightness") is 3.4.

2. It looks as if you are making the common error of failing to account for the extremely large effect of filament luminance on beam performance. As voltage drops, luminance drops off very steeply and beam performance nosedives along with it. As voltage increases, luminance and beam performance rise very steeply. It is inaccurate and misleading to leave out this factor and refer only to the percentage intensity loss or gain with voltage change. 1000 lumens with low filament luminance gives much poorer seeing performance at night than 1000 lumens with high filament luminance, and there is substantial crossover as well; 700 high-luminance lumens can give better seeing performance than 1000 low-luminance lumens.

Sehr gut! Please post links; I can alway use this type of info.
I've never heard of high luminance luminous flux; are you referring to the luminosity curve?

If you have current headlight specs please post them; I think I can measure intensity using a digital camera as a light meter, maybe using sunlight.

simply ridiculous
those people that lead decidedly non-Cartesian existences.)

Ad hominem?

And you are still framing this as an indignant angry parent (you) scolding a clueless child (me).
The usual way of handling this is by interpreting your behavior back to you (Process Commentary) but there are other options. I figured interpretation would get you off of me in the least amount of time. We'll see.

 

[bizzel]

I'm still wary of the idea of putting another 400-600 watts of load on the stock alternator. That's a lot of unused overhead to be built into the original design if you ask me.

 

[Alaric Darconville]

I'm still wary of the idea of putting another 400-600 watts of load on the stock alternator. That's a lot of unused overhead to be built into the original design if you ask me.

It'd be some work and money, but adding a second alternator and battery (with isolation) specifically for the off-road lamps could make sense (depending on how much you'll really use them). More points of failure, sure-- but better than the single point of failure failing. The second alternator need not be extremely powerful, and a motorcycle battery would probably be just fine (or as small an automotive battery as can be found). This will keep the load off the main alternator, and the secondary one would be mostly 'freewheeling' when those off-road lamps are off.

 

[Alaric Darconville]

I would also control brightness not by dimming multiple lamps (even through more acceptable methods like rheostatic control on properly sized wiring, or better yet, PWM) but by controlling the number of lamps lit. This would result in higher electrical efficiency, and the lit lamps would still have the 'punch' needed to light up distant objects. The light would also not lean towards the red/orange/'brown' color that results from a filament not getting heated properly. There would be less blackening of the envelopes. (This brings up another point: Automotive bulbs, especially "long life" bulbs, have outlived their usefulness long before they've stopped lighting up, thanks to filament evaporation and bulb blackening. (Long life bulbs start off as craptastic anyway, due to the pitch and mandrel ratios necessary for longer life also reducing filament luminance and beam focus.))

Although we're talking about "auxiliary lights", any additional lights installed on a vehicle should certainly not be crap, as they'll merely offer a false sense of security at best, and at worst, actually detract from safety.

 

[guiri]

Mine have an override switch and I only turn them on/flip the switch when I'm on country or empty roads

 

[guiri]

I'm still wary of the idea of putting another 400-600 watts of load on the stock alternator. That's a lot of unused overhead to be built into the original design if you ask me.

I specifically asked this question at my ford service and they said that they had a ford time warner truck with the same alternator that was running all kinds of stuff so I would be ok.

 

[Alaric Darconville]

I specifically asked this question at my ford service and they said that they had a ford time warner truck with the same alternator that was running all kinds of stuff so I would be ok.

How many amps is that alternator rated for? Also, it's just one truck, it's not a statistically significant sample.

 

[guiri]

Dunno, I can find out. I know the ford forum says it's probably not enough but before I upgraded to a different alternator, I thought I'd ask THEM. I also have full bumper to bumper extended warranty so if it takes a dive, they'll be putting a new one in, ESPECIALLY since I asked them about it. Before he said it was ok, I was going to get a 200 amp alternator

 

[xul]

The switch contacts should be rated for 'a tungsten load'. For very large alternators you may need a different crankshaft pulley.

 

[guiri]

Well, I guess I'll ride'r till she bucks because this is getting too complicated for me..

 

[deadrx7conv]

I'd wager that your dealer is clueless.

Aftermarket add-ons could NULL AND VOID MANY WARRANTIES. If the alternator fails, you are at the mercy of your dealer.

When the alternator fails, simply locate a higher-amp replacement.

A vehicle that can tow usually has some alternator reserve capacity for all the trailer lights and equipment. You should be good as long as you're not idling around much. You should also make a habit of shutting down the lights a certain distance from home to make sure the battery is charged back up. A bigger battery will also give you more reserve in case you are light abusive with a weak alternator.

Visit several automotive stereo shops. They tend to have alternator/battery experience, along with 2nd battery, isolator, or even independent 2nd alternator/battery experience. Or, they might also be able to find a 5-10% smaller alternator overdrive pulley to spin it a little faster.

 

[Lynx_Arc]

Well, I guess I'll ride'r till she bucks because this is getting too complicated for me..

I ran 2 100 watt halogens with little problem off a 60 amp alternator. I did have to idle it faster when running everything on the car in the summer (AC, headlights, stereo, etc). Check your manual and find what your alternator is rated at, sometimes they offer higher output alternators on cars like police interceptors and such that are essentially almost a direct swap and can boost output considerably. I remember back in the 80s I had a 60 amp alternator and a friend that bought a police interceptor at an auction had a 100 amp alternator in his car. I would bet with all the electronic and computer stuff in cars today that 120 and 140-150 amp alternators are not entirely hard to come by. It may be as simple as going to a salvage yard and finding a junked police car with one or maybe a diesel powered vehicle may have a larger alternator.

 

[-Virgil-]

Sehr gut! Please post links; I can alway use this type of info.

Links to what?

I've never heard of high luminance luminous flux

The phrase "high luminance luminous flux" does not appear in my post, and the phrases that do appear don't mean anything when taken out of the referential context in which they were written. Please re-read the post you are having trouble understanding.

If you have current headlight specs please post them

I am not sure what kind of specs for which headlamps you are asking about.

 

[guiri]

I'd wager that your dealer is clueless.

Aftermarket add-ons could NULL AND VOID MANY WARRANTIES. If the alternator fails, you are at the mercy of your dealer.

When the alternator fails, simply locate a higher-amp replacement.

A vehicle that can tow usually has some alternator reserve capacity for all the trailer lights and equipment. You should be good as long as you're not idling around much. You should also make a habit of shutting down the lights a certain distance from home to make sure the battery is charged back up. A bigger battery will also give you more reserve in case you are light abusive with a weak alternator.

Visit several automotive stereo shops. They tend to have alternator/battery experience, along with 2nd battery, isolator, or even independent 2nd alternator/battery experience. Or, they might also be able to find a 5-10% smaller alternator overdrive pulley to spin it a little faster.

This assumes I have money to spend which right now I don't. Also, I'm sure the dealer is clueless BUT, that is why I ask and if something happens, I'm going ape$hit on them and I WILL get it right, especially since I have a voice mail from them saying that there's plenty of power

Yes, I would love a bigger alternator and that may still come but here's the thing, IF I get one and something happens because of it, THAT can void my warranty. This apparently won't..

 

[guiri]

I ran 2 100 watt halogens with little problem off a 60 amp alternator. I did have to idle it faster when running everything on the car in the summer (AC, headlights, stereo, etc). Check your manual and find what your alternator is rated at, sometimes they offer higher output alternators on cars like police interceptors and such that are essentially almost a direct swap and can boost output considerably. I remember back in the 80s I had a 60 amp alternator and a friend that bought a police interceptor at an auction had a 100 amp alternator in his car. I would bet with all the electronic and computer stuff in cars today that 120 and 140-150 amp alternators are not entirely hard to come by. It may be as simple as going to a salvage yard and finding a junked police car with one or maybe a diesel powered vehicle may have a larger alternator.

I just checked. Standard (which I have) is 110 amps and you can get much bigger ones. Matter of fact, this guy in one of the forums has DUAL 175 amps on his. I was gonna buy it but didn't have the bucks. I also want to add a second battery

 

[Lynx_Arc]

I just checked. Standard (which I have) is 110 amps and you can get much bigger ones. Matter of fact, this guy in one of the forums has DUAL 175 amps on his. I was gonna buy it but didn't have the bucks. I also want to add a second battery

110 amps? That could possible be enough to run an extra 30 amps of lighting or so depending on how much power the rest of your vehicle takes. As far as an extra battery it won't be needed if you have enough alternator power and only run the lights with the engine on.