OffRoad Light Bar - Page 1
Forum section: electronics / beginners

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 05:23:59 am
content: Okay, So I ordered a 52 inch Off Road Light Bar. I was excited to open the package today.However, now the concerns set in.They claim it is 2100W light output. 300 LED's at 7W each. They are CREE (so they claim).At 12volts, that should be about 175A, correct?Well, that should be ran with 4GA wire for a run of about 7-10ft of wire to safely operate it for both ground and power wire.Well, It came with a wiring harness which consisted of a 30A fuse, 40A relay, and 17AWG wire.WTF? Is this thing going to be safe running with that wire harness?I think the largest Relay I can even get is a 100A, and even at that, I'd have to get a large Maxi Fuse or ANL Fuse for a 175A Fuse. And 4GA, well, I'd have to drill through the roof to run that size wire, instead of being able to run it through the window seal and down the door pillar, which I had planned to do. There's 17AWG wire going into the Light Housing as well, from the factory, so I'd have to crack that thing open and rewire it and figure out how to reseal it, then there's the circuit board, was it done correctly to handle that power?

author: Unknown
author_rank: Unknown
timestamp: July 11, 2017, 06:00:59 am
content: How long could you sustain >150A on your alternator/battery? I think some bus and truck alternators (or dual alternator setups, etc.) have that much output, but that doesn't seem like the typical vehicle for an off-road light bar.In any case why not power it up (perhaps with something a little better than 17GA wire... really?) and see what happens? If it blows the provided fuse you could just return it, and if it doesn't then I would suspect 2100W is just some bogus marketing number.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 06:08:32 am
content: Well, there are 300 LED (i counted), Whether or not they are CREE or are 7W, I don't know. It is 17AWG wire, says it on the wire itself.The Alternator is high output. The truck is a dual battery Turbo Diesel. So I'm not worried about sustainability of lighting. I can always add another alternator if I have to later.I'm more worried of the wiring catching on fire and burning the truck to the ground. It's obviously working. People are buying these things and hooking them up all over the world. Even on that 17AWG wire. I just don't think it is very safe. I could upgrade the wire, and even maybe the relay/fuse, but the wire going into the housing of the Light Bar, I can't or not going to. Not going to void the warranty.

author: boffin
author_rank: Unknown
timestamp: July 11, 2017, 06:10:06 am
content: Quote from: Falcon69 on July 11, 2017, 05:23:59 amMy guess is that it's 2100W 'equivalent (incandescent)' , so divide by about 8, for about 260W actual power @ 12v, or just over 20A

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 06:12:49 am
content: Quote from: Falcon69 on July 11, 2017, 05:23:59 amHook it up and test it. I'll lay odds your 2100W rating is "The equivalent of 2100W of Halogen" and that thing would be lucky to draw a tenth of that.Every cheap crap LED light I've ever seen supposedly has CREE LEDs.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 06:13:26 am
content: If you mean Lumens, it says 325,500 Lumens

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 06:15:07 am
content: So, are you all saying, go ahead and ditch the included wiring harness, just keep what it came with coming out of the lightbar itself, and get some good 12 or 10ga and wire it all up with the 40A or 60A relay and call it good?Or is the included 17awg harness going to be good enough? It seems awfully small to me.All I know is when I hooked up my 55W HID's on my car, It was 12GA wire if I remember correctly. That was for just 55W.Even if actual 260W, 17AWG is still awfully small? I think I would still need to upgrade to at least a 12ga wire.

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 06:39:36 am
content: Quote from: Falcon69 on July 11, 2017, 06:15:07 amNo, I'm saying stop pontificating, connect the thing up and *measure* it. Until you actually _know_ what it draws you are pissing in the wind. Once you have a number, you can work towards the right way of hooking it up.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 06:41:47 am
content: I don't have any way of measuring it. My multimeter won't do it. I don't have one of those ones that wrap around the wire (hall effect one?) and measures it.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 06:57:06 am
content: Trying to find a review of this on Youtube, but isn't one. It's the 9D Quad Row Curved 2100W LED Light Bar. eBay shows many of them sold, yet no Youtube reviews been done to see them in action.Guess I may Have to be the first.So, question though...Will the wire just get warm, burn up, or light not 'light' to it's full potential if wiring too small? I'll hook it up tomorrow, took all day to drill and put in the threaded inserts (and brackets still don't quite fit right, have to fix that).

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 06:58:55 am
content: Quote from: Falcon69 on July 11, 2017, 06:41:47 amI wouldn't worry. I just did a search for "52 inch cree off road light bar 2100w 325500 lumens" abd turned up a whole host of over-rated cheap garbage. Digging further to find some quality units of similar size with real & vaguely credible specifications turns up specifications in the order of a couple of hundred watts and about a third of the rated light output. If those led's in that unit were 1W each I'd be surprised. So you'll be looking in the order of 20-25A. In the park for the fuse that came with the light. Additionally, they are rated at somewhere between 9-30V so they'll have constant current LED drivers in there. Don't worry so much about volt drop on the cable, just make sure it won't catch fire.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 07:01:50 am
content: Okay, thanks BradC, I'll let you know how it goes.It does look 'Badass' up there though. Sure looks better then the old style 'KC Hi-Lites' that used to be. Man those things were big and ugly, but got the job done. These new LED technology ones are just so much smaller and more light oputput, less energy.

author: ruairi
author_rank: Frequent Contributor
timestamp: July 11, 2017, 07:05:15 am
content: This will definitely be "equivalent" watts to incandescent/Halogen, not a reflection of actual output power.Where are you based? Can you borrow a clamp meter?Cheers,Ruairi

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 07:06:18 am
content: Quote from: Falcon69 on July 11, 2017, 07:01:50 amI'd be interested. I've kinda been looking at one of the cheapies to try and unobtrusively tuck under the bumper of my car for when I do late night country runs. I wouldn't use it enough to justify a decent one, and it's stupid the amount of these that get nicked.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 07:09:36 am
content: Ahh, yes, Clamp Meter,. that's what I was trying to remember what it was called. Nope. Don't know anyone locally who has one. But, I may Be able to find one to buy off Craigslist or somewhere tomorrow if they cheap enough.And Bradc, they guy had this listed at $185, i offered $170 and he took it. Spendy, but still much cheaper then spending $1000+ for one of the Rigid ones (those ones are really nice).But now that I look at it on this Full size F250, I should gone with a 54". the 52" kinda looks small believe it or not.

author: djococaud
author_rank: Regular Contributor
timestamp: July 11, 2017, 07:10:12 am
content: If it really draws 2100W (which I really doubt) on a 52 inch bar, I would hope there is a fan in it because it will have to dissipate an awful lot of heat !I would definitely test it and measure the current to be sure. (having even a cheap clamp meter can always be useful in the future, especially if you work on a tuck, a measuring tool is never wasted money...).If it comes with a 30A fuse that does not blow, then goes with a 40-50 Amps wire (the bigger the better for low voltage drop though).

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 07:13:00 am
content: Just for giggles, here are some realistic numbers from units with real high power (>1W) LEDs.http://lightbarreport.com/best-50-inch-led-light-bar-reviews/Check the power consumption vs the illumination output.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 07:20:25 am
content: ya, those are low Lumens compared to what mine is 'suppose' to be rated at. 325,500 Lumens. But I beleive you guys are right. Those figures are way over exaggerated. Chinese numbers are not the same as the rest of the world numbers.

author: Falcon69
author_rank: Super Contributor
timestamp: July 11, 2017, 07:22:14 am
content: Sears has a Craftsman Clamp Meter that measures up to 800 AC/DC amps for $100, Homedepot has a Klein Tools one that Measures up to 600 Amps for AC/DC for $120. Think I may get the Sears one. You guys are right, I could always use it later for other projects.

author: BradC
author_rank: Super Contributor
timestamp: July 11, 2017, 08:08:32 am
content: Quote from: Falcon69 on July 11, 2017, 07:20:25 amYeah, 325,500 Lumens PMPO.

author: Zero999
author_rank: Super Contributor
timestamp: July 11, 2017, 08:55:25 am
content: Quote from: boffin on July 11, 2017, 06:10:06 amYes, it it really does give 2100W light output, then you'd be looking at several times that of electrical power.

author: stevelup
author_rank: Regular Contributor
timestamp: July 11, 2017, 12:43:30 pm
content: http://www.ebay.com/itm/9D-Quad-Row-2100W-CREE-52-Inch-LED-Light-Bar-Flood-Spot-Driving-SUV-VS-50-54-/152591762255Looking at the photo, they're just little SMD LEDs - there is absolutely no way on earth they are 7W each - it's total fantasy, and that lumen figure

author: rstofer
author_rank: Super Contributor
timestamp: July 11, 2017, 01:40:25 pm
content: Spend a very few bucks and buy a current shunt. The one linked here will have a 75 mV drop at 200A. Just in case your bar actually draws anywhere near that amount.https://www.amazon.com/DMiotech-current-shunt-resistor-Ampere/dp/B008SOXFZCYou could also buy a 100A shunt and just assume you're going to overdrive it briefly (also unlikely!):https://www.amazon.com/DROK-Anti-Rust-Electric-Resistors-Resistance/dp/B071CQV1TTFor this 100A shunt, each mV you read across the shunt corresponds to 1A of current. It is helpful if your meter has a mV range.I think I might go for the 100A shunt and probably a 20A shunt. I seriously doubt that the light bar takes 175 Amps.Shunts are handy things to have around for just this kind of project.

author: Falcon69
author_rank: Super Contributor
timestamp: July 15, 2017, 04:31:19 am
content: I have not gotten around to hooking up the wiring. I had to design a new bracket, as the one I purchase made the light point too much downward and no adjust-ability. So I'm waiting on that to come from the Laser Cutter shop. Also, I decided to sand down the bed and rocker panels of the truck to spray on the BedLiner while I have nice weather outside.But, I did get a response back from the people I purchased it from, voicing my concern about the small gauge wiring possibly overheating and catching fire because of too many amps that may try to run through it, here was their response (which is exactly what I'd thought they would say, they have no concept of OHMs Law):"Please don’t worry dear.We have being selling this item for a long time.There is never such case happened.it's plug and play, just please don't worry dear, we produce the light ourselves, we will have a text before, we will not and dare not to sell hazardous goods.Can you have a try and tell me whether it work well?"Yes, that's THEIR bad grammar, not my bad spelling.

author: ConKbot
author_rank: Super Contributor
timestamp: July 15, 2017, 05:10:20 am
content: I'll put my bet on about 5-10A actually being drawn. 300 LEDs, 3 in series, 100 in parallel, 50-100mA each. It would match up with 17 awg wire pretty well too.

author: Falcon69
author_rank: Super Contributor
timestamp: July 15, 2017, 05:19:14 am
content: hadn't thought of it that way, it's a possibility.that's a possibility. If the truck puts out 13.8 volts (average), and these LED's have a forward voltage of 3.2 volts or so, there could be 4 of them in series. These are small, so I doubt they draw 100mA, 50mA could be about right.So, at 4 in series, that's 300/4 = 75so 75 in parallel75x50mA=3.75ASo Even if each LED was at 100mA each, that's only 7.5ASo, looks like you may be right. Should be okay, even on that 17AWG wire.But, I still need to buy that clamp meter to make sure.Now I'm tempted to break it open and see exactly how these are wired up on the circuit board. Damnit, I don't have time for this! LOL

author: WastelandTek
author_rank: Frequent Contributor
timestamp: July 15, 2017, 05:24:22 am
content: I smell marketing wank, maybe we need a new unit; the marketing Watt, equal to .01 real Watts.

author: Falcon69
author_rank: Super Contributor
timestamp: July 15, 2017, 05:31:19 am
content: ya, I smell it too. I don't think this thing puts out the true 2100W it claims. I think it's more like others have said and is actually watts in Halogen. These LED's only measure about .125x.125 inches. Pretty small. I may just pop this thing open after I spray the bedliner stuff, as I can't really drive the truck for 3 days after that, as it needs time to cure. So, I'll have some time to break this light open and give a tear down review of it. I'm interested to see if these are actually CREE LED's. I've read, watched, and heard from others that they are better LED's for these lights than Phillips and Osram. I specifically ordered (and paid alittle more) to have CREE.But hey! If it lights up my entire block and then some, good enough for me!I'll get it wired up soon, I'm kinda holding off, because I am installing an alarm, stereo system, and other offroad lights and winches (yes, two, one in front and one in back). So I was kinda holding off to do all the wiring at once, as I need to figure out how I'm doing my switch panel too for everything and fuse blocks.

author: stevelup
author_rank: Regular Contributor
timestamp: July 15, 2017, 08:11:13 pm
content: If that thing lights up your yard properly, let alone your whole block, I'd be most surprised