I probably will still wire it into the dimmer switch as it wouldnt be much more wiring as I would just have a toggle switch inline of the signal wire coming off the dimmer switch.

Thats right, this light has a working range of 10 to 30 volts. But I found another guy selling this for way more money but he listed the power consumption as being close to 10 amps because of the 111 watt rating.

This is where I am confused because I converted most of my exterior lights on my Mercury to LED and used 80w Cree LEDs. They stressed in the description from the manufactuer in china that they are not consuming 80w but that is the light out put is 80w. They list the power consumption as actually being 7 to 9 watts and 0.63 amps @ 12 volts. Now if this is the case then how could a 111 watt spot light be consuming close to 10 amps of power when I have a 80w Cree 1156 bulb for my cornering lights that has 16 pieces but yet is only consuming 0.63 Amps @ 12 volts. Something doesnt seem right here and I am wondering if those spotlights I found that everyone else is selling for $400 and up for a pair but this guy is selling for $30 a pair is really using Cree LED`s. I think the guy on the other site just simply used the 111 watt rating which is just like the 80w rating on the 1156 bulb I have which is 5w Cree LEDs x 16 of them equal 80w. In this case its 3w Cree LEDs x 37 of them equal 111w.

This is where its easy to figure up the amperage wrong on LEDs as the wattage they are listing from personal experience is always the output not the power consumption. If they were consuming that much I think my Mercury with its factory 75A alternator couldnt keep up with four 80w LED bulbs. I will find out for sure when I go ahead and buy four of the red ones for my tail lights but I dont think they are pulling down that many amps and I dont think the spot lights are pulling down close to 10 amps a piece if thats the case then they are consuming as much energy as a 100w halogen bulb which just wouldnt be correct.

I also found out the other people selling the same exact lights, they are selling them with exchangeable lenses to change them from spot to flood. I need to email the guy if I ever get a response to my initial email to see if they come with those lens if they do then I can play around with a combination of spot and flood or all flood or all spot to see which seems to work the best. Based off the test photos I saw the flood lights dont really throw the light out its just a more diffused light and you dont have a hot spot as you do with the spot light.



Only thing is I am just wondering if I should just go ahead and pull the trigger on this and just order the lights I found. They are cheap so if they burn out I can always buy another pair for $30 and replace them as they go out. But it comes back to I want to question this guy and find out if he can tell me the actual wattage consumption and or amperage consumption. Then I will question him about the lens, that I saw others selling the same exact light and if these come with the flood light lens that bolts in ontop of the spotlight lens.

 

Light output is never rated in wattage...that is ALWAYS the power consumed. If can give us a rough idea of lumens, or that a 40w bulb is about twice the brightness of a 20w bulb.

Anyone who claims that any normal LED driving light are 'putting out' 80w is basing this on lumen equivalence of an 80 watt halogen bulb.

And you should avoid buying from this guy, since he should be telling you the output in lumens. Power consumed is rated in watts. Period.

As far as working range of LEDS...this is where it can get confusing as I will explain in my next reply.

111 watts worth of power consumed on your setup will be drawing somewhere around 8-9 amps at normal operating voltage as I stated.

 

I used 13.7 as an average value for a properly charging vehicle system. It can vary from that, of course.

Working the formula the way I worked it, I am correct.

IF you plug in different numbers, and solve it the other way around, then yes, you will arrive at a different current rating. We have to assume the voltage is more or less constant, and then solve for current based on stated wattage.

As far as your statement that "no light is going to draw more current as the voltage goes down"....in the case of regulated LEDs thats exactly what some of them do.

As supply voltage goes down, (a volt or two) the regulator will allow more incoming current to compensate, keeping the brightness pretty much the same. Inversely, as supply voltage goes up, (sometimes to 24 or 30 volts) the regulator circuit throttles back on incoming current, so that the lumen output and the overall power consumed is more or less a constant flat line. If higher supply voltage was directly applied to the LED modules, they would be fried in short order. Keep in mind that some linear regulators simply dump excess input current as heat into the heatsink, but digital regulator circuitry is more efficient.

There is a working range for the regulator, and outside of this range, the lumens will either drop off sharply, as is the case with low voltage, or the LED module will probably be damaged if the supply voltage is way too high.

Remember these are electronic devices with imbedded regulator circuitry, that applies a stable 2v or 3v (regardless of supply input) to the LED junction, not simple incandescent bulbs which run on 12-14 volts.

 

I haven't shopped for automotive LED lights, but I know it's really common for non-incandescent bulbs for other applications to report light output in watts, meaning that a 100W LED bulb puts out the same amount of light as a 100W incandescent bulb. It's not technically correct, but then again, neither are most customers. If a seller listed light output in lumens most customer's eyes would glaze over and they'd doze off. So I wouldn't necessarily stay away from a suplier simply because he tried to speak a language he thought his cutomers would understand.

By the way, in my earlier post I was thinking about lights rated to consume 111 watts of power. Unless you know at what voltage they consume that power you don't really know exactly what amperage they'll draw. If you go higher or lower than the rated voltage you'll consume more or less wattage (respectively) and that will affect the current draw.

 

My bad. I missed the fact that he was asking about 111W LEDs. I don't think anyone makes automotive LEDs that consume 111W of power so I assumed he was talking incandescent. As he clarified above, he was talking about LEDs that are rated to put out 111W of light (which is a goofy way of making things clear to the average consumer). In that case, he's right in his original statement that you can't use light output (whether measured in watts or lumens) to determine current draw.

 

We are gonna have someone accuse us of hijacking this thread, but the fact that some shady sellers on ebay rate an LED for a headlight at 80 watts means that that seller should be avoided, unless it somehow actually DRAWS 80 watts of power. Rigid industries rates its LED lamps in wattage consumed, but lumen OUTPUT...and an extremely bright LED lamp might only draw about 15 watts, but puts out the power of an 80 to 100 watt halogen.

In fact, an 80 watt power resistor in a power supply puts out ZERO light.....(other than infrared, if you want to count that.)

Wattage is NOT light output...EVER. Yes I know some sellers use this as a benchmark, since most buyers know that they have 55/60 watt headlights. They have no idea what the lumens are...and to tell the truth, neither would I unless I saw it on the package.

BTW...IF you had a TRUE 80 watt LED array, or a single 80 watt LED module, I can guarantee it would be many times brighter than an 80 watt incandescent, since LEDs are so much more efficient at converting electricity into light.

 

111 watts was the sum of 37, 3 watt Cree LED units in an array, and a 3 watt Cree unit is always drawing about 3 watts. It is a true power rating, NOT a brightness measurement...I can assure you it is WAY brighter than a normal 3 watt Christmas tree bulb.

Stated another way:

A 111 watt array of Cree modules will put out a LOT more light than a 100w, or 2, 60w Halogen lamps.

But in either case, the current consumed is roughly the same.

 

I dont either, I see quite a few listing the wattage as you would buy house hold bulbs. But the problem I come into is that the spot lights I found that a guy is selling very cheap and I really want to buy, they are listed with the following specs.

Wattage : 111 (3w x 37 Cree Chips)
Lumens : 9,300
Voltage : 10 to 30

This one seller I found listed the amperage for these as being 8.67 Amps at 12v. This is where I am not believing this because I bought a 1156 LED projector bulb for my Mercury with the following specs.

Wattage : 80 (5w x 16 Cree Chips)
Lumens : 1,200
Power Consumption Watts : 7 to 9
Power Consumption Amps : 0.65 @ 12v

Now this is why I am confused on this because here I bought a LED bulb that is using 5w Cree chips and is only consuming 0.65 Amps @ 12v but is listed as 80w. But then this spotlight I am looking at is using 3w Cree chips and is consuming close to 10 amps @ 12v. I just dont see how that can be possible when the wattage output between 80w and 111w is just 31w. I am thinking the spot lights should be consuming around 1.2 amps a piece considering an 80w LED bulb I have rated at 1,200 lumens is consuming 0.65 Amps @ 12v.

If these truely are consuming just under 10 amps of power then I think I should just forget about these and get the KC Daylighters that use a 100watt H3 bulb. I honestly cant afford to run 40 amps of aux lighting with a stock 60amp 1G alternator. Big reason why I had my sights set on these LED spotlights as I figured they would be about 1 to 2 amps per assembly and mirror the 1156`s I bought that uses sixteen 5w Cree chips for a total of 80w output but is listed as consuming only 7 to 9w and not even three quarters of an amp.

Thats how I figure this is, is these lights are being listed by the light level they produce wattage wise but not their actual watt consumption. But now I am not too sure if I want to take that risk and end up with four spot lights that I will never use as they consume too many amps for my taste for a LED spotlight.

So what you are saying is that reguardless the number of Cree chips and the wattage they are rated at is the watts they will consume?

If so then that would mean the listing for the 5w x 16 Cree Chips 1156 bulbs I bought come out to 80w total but they were listed as consuming 7 to 9 watts, and only 0.63 Amps @ 12 volts would be incorrect and be nothing more than a lie then.

I want to find this out because I have no problems running the LEDs I bought for my Mercury with the orignal 75 Amp alternator but now the 60 Amp alternator on my truck might be another story as I am trying to keep the total amperage for my lighting to be under 15 Amps. I am at 9.375 Amps with my headlights on high beam. That gives me 5.625 Amps left over to play with for my Aux lighting. Which is why if these spotlights are consuming 8.67 Amps @ 12 volts are already past my limit for just one and I plan on mounting four which puts me at 34.68 Amps total which is over half the capacity of my Alternator. I might as well go with Halogen bulbs then seeing as I am at 32 Amps total with four Aux lights, which in my opinion basically is telling me LED`s are not as friendly on power consumption as I once thought then. This is all bearing on if the 80w 1156 that I bought really is not consuming 7 - 9 watts and 0.63 Amps @ 12 volts while having sixteen Cree Chips at 5w.



But I am curious if I were to just say screw it and purchase these lights, is there any other way to test the amperage consumption of these other than using a inline fuse jumper wire to power them up and go down in fuse size till it blows?

 

Duplicate post removed.

 

Ok. Here we get to drill deep into it.

"Wattage : 80 (5w x 16 Cree Chips)
Lumens : 1,200
Power Consumption Watts : 7 to 9
Power Consumption Amps : 0.65 @ 12v"

This list of data is bogus as is, but would be viable if the first line were omitted, this is why I said avoid these sellers who quote impossible or non-sensical data.

You can't have it both ways...if the claim is the LED is consuming 7-9 watts, it CANNOT also be drawing 80 watts. It might be according to the seller, 'putting out 80 watts of light' but this is partly BS. LEDS put out much more light per watt consumed than any incandesent/halogen lamp. Period. But again, lumens are used to rate illumination, watts are used to rate power consumed...or sometimes, power available to be consumed, as in a power supply. But LED's dont waste energy as heat the way an incandescent bulb does. So...more of the energy consumed is used to produce light.

I'm sorry your sources are confusing you about all this. I did not see the ad for the 5w x 16 cree leds so I cant tell what is being sold there. But throwing in all the ads you have seen, with questionable data, and the 1156 chinese bulbs is not going to help you understand what you really want to know. Some vendors of those cheap 1156 and 1157 LED inserts are duping consumers with bogus claims.

If you have 5.6 amps left for lighting, that is good for about 76 watts...so...buy your lighting based on this figure, and use the data for power consumed, not the extraneous BS about the power the light produces.

As far as measuring amperage you simply need a digital meter with a 10 amp scale and you insert the leads inline with the load to figure current draw.

Also, just to confuse you more...alternators are rated at PEAK output...they dont, and cant, put out that rating for very long.

A 75 amp unit might taper off to 20 amps and live quite happily, but if it has to constantly put out 70-75 amps all the time is will have a short service life.

You are wise to want to keep your lighting modest. I would recommend two RIGID dually D2 spot units, and they draw about 15 watts each, about 30w for a pair, well under your wattage ceiling. I love the set that I have on my van, and also on my sidecar motorcycle.

They are wonderful lights. Roughly $200 for a pair but that includes sturdy brackets and a full wiring harness.

 

Another recommendation for the Rigid lights.

As Brian said, stay away from maxing out your alternator.
Not only will it struggle and overheat, it will be a constant load on your engine.

I=V/R, Ohm's law is pretty simple.
If some joker on the internet wants to try and sell you 111w LED spotlight you could probably illuminate the dark side of the moon.

Incandescent lights waste (about) 95% of their consumed wattage creating heat and IR that we cannot even see.
If a typical LED is only 30% efficient, that is still a sixfold increase in light produced per watt.
Cree recently developed a white LED producing over 300 lumens per watt!

 

I will look into that. In the mean time, work has been dead slow so far so I did some math and some quite needed thinking. This is what I have came up with so far.

If I go with these 111w spotlights instead of running four of them on the roll bar consuming 34.68A @ 12.8v or 32.17A @ 13.8v. I can run two of them mounted on a pushbar which I really do want to get as well and go for a baja look with just the lights on the rollbar. This will put me at 17.34A @ 12.8v or 16.08A @ 13.8v.

This running two lights like this in conjunction with my headlights on highbeams I will be looking at a total of 26.72A @ 12.8v or 24.78A @ 13.8v. If I am putting out 14.8 volts then I would be looking at 23.11A then.

I need to do the math on the LED lights I did on the interior to figure out what my amperage is there and figure in my parking lights, tailstop lights, and side marker lights to get a full picture of exactly what amperage I am looking at for just the lights alone.

I also did a little searching for alternators, I found where I can get a 100a 1G alternator that will be plug and play without modifications that on the data sheet lists 65 Amps @ idle. I personally think that would fit the bill and provide more cushion seeing as this truck is a very bare bones truck with dealer A/C and I am just wanting to add a few more lights.

Only thing that I am concerned about is if 9" spot lights will be too big to mount on the bottom tube of those dual tube pushbars that I see lots of people have for these trucks that I plan on having made or making myself.

Well your post is the one that made me start rethinking having four of these mounted on a rollbar. My friend at work does off roading and he has a pair of those small four LED rigid square LED lights mounted up front and he was telling me that he could be the 5th vehicle in a line of vehicles off road and his lights would light the way for the lead vehicle even and his is only putting out around 1300 lumens. So I figure if I do two of these spotlights on a pushbar (that is if 9" isnt too big of a light to fit between the tubes of the style of pushbar I will either have made or make) I would still exceed his lighting as I would be at 18,600 lumens.

I also think I will be doing an alternator upgrade, but I dont think I will go crazy, I have been doing some reading last night on many different ford related sites and found that I can get a 100A 1G alternator that puts out 65A at idle which I think would fit the bill for what I need. I probably would be fine with two spotlights and the stock alternator but I rather provide as much cushion as possible for my charging system as I still havent desided if I want to mount a CB in the truck or if I want to go with those 100/55w Hella offroad H4/9003 bulbs for the headlights I will be ordering today.

I also found a external regulator that is listed as being set at 14.8v which has me curious if my oem orignal motorcraft regulator is putting out 14.8v, if I can get 14.8v while running then the amperage I will be needing will go down some and help me out.

I just have two concerns one is if the 9" spot lights will fit between the two tubes of the style of pushbar I want to have built or build myself, and the other is if I will have an airflow issue on the highway with two of these 9" spotlights being mounted infront of the grill.

 

What is the cost of having a 1G made to throw 100 amps? I ask because a good 3G is about $125, and an upgraded 3G capable of 160 amps is more like $200. With no external regulator to worry about.

Also, if you run 14.8v for very long you'll boil the battery dry.

 

The one I found for 100A with 65A at idle has a price tag of $155. When considering that I could get a good 3G for $125 then have to buy wire to cut and splice the orignal harness, then the fact that I would have to have the ammeter reworked into a volt gauge, the more economical solution is to go with this 100A 1G alternator that will be a simple bolt in.

To help out I could replace the factory charge wire from the alternator to the solenoid or add a second one to reduce the likelihood of the higher amps causing an issue.

I know Powermaster recomended to upgrade to a 8 gauge charge wire. I think I might do that anyways even with a 100A alternator just as I feel overkill is better than underkill.

I also think 65A rating at idle would be well over enough for what I plan on adding. I dont know if it would be 14.8v but I know the regulators I found for a 1G alternator that is heavy duty are listed as being set at 14.8v. I know Ive seen cars and trucks at work that alternators put out between 13.8v to 15v.

I just need to find someone on here that has one of those dual tube pushbars and ask them if they could measure the distance between the two bars before I pull the trigger and order these 9" spotlights. I am afraid that I will get them and then get the pushbar built later on and the spotlights wont fit how I want them.

 

Your ammeter and shunt are not going to like 100A. The shunt, which is a fancy name for a resistor, is sized to give full scale on the ammeter at about 65 amps. So the ammeter will peg hard, but the shunt may overheat and melt down - if you put all 100 amps through the shunt.

However, here's how it is wired. At first blush it would look like you are safe since the stuff going into the cabin doesn't go through the shunt, just that going to the battery. But, you are planning on installing headlight relays, and if you take the source off the solenoid post then everything going to the headlights and off-road lights will go through the shunt - as well as the charge to the battery. So, if you've cranked it hard and pulled the battery down when it finally starts you'll throw many amps toward the battery. And if you pull out the headlight switch then all of that current will go through the shunt - in addition to the charge to the battery.

That's not something I'd want to do as the shunt was not designed for that much current. I think it is 3G time. Wire it correctly and convert the ammeter to a voltmeter. That way it'll work and if the alternator goes out on a trip you can easily get a replacement.