LED lightbar power/current draw - Claimed vs Actual

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I bought a 4 inch 60W LED light off eBay recently and thought I'd do some measurements.
V = 12.7V
I = 1.2A
P = 15.2W

So about 1/4 of the claimed specs.
What's your experience?

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How did you get the wattage its using? Ohms Law calculation? I=V/R ?
Remember as they have Drivers LED use a lot less power than Halogen bulbs.

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I used a power meter. The values were from the readouts.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

Like the 4wd super centre that has 9" lights that put out 9062 lumens........... at 32.01Volts?

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That's next on the list to be tested. But I can't measure lumens.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

I have the LED215's and I'd be interested in the real world light output of them vs 215's or Intensities.

Intensities would be better for a 'seat of your pants' test though with the same 6400K (mine are 5000k).

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See here https://www.4x4australia.com.au/gear...hts-comparison

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

Yeah saw that one as my lights won but I wonder how well the bottom-end of the market (price-wise) performs.

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I was expecting a comparison with the more "popular" lights too ....

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

If they don't show the real power consumed on the specs it will be the max theoretical power the leds can be driven at, ie if you take the number of leds, ie 12 and multiply it by 5W you''ll get the claimed power the number of leds it will most likely work out to the "claimed" power. of 60W.

To extend the life of the leds most manufactures de-rate the drive power to say 70%, many
using cheap leds etc de-rated it a LOT more.

If they don't show the actual current drawn in the specs ask them what it is or steer clear of them.

[dBC Member Find all posts View Profile Close dBC]

I bought a 4 inch 60W LED light off eBay recently and thought I'd do some measurements.
V = 12.7V
I = 1.2A
P = 15.2W

Have you got a pointer to the light? Is it something like this:
http://www.ebay.com.au/itm/2x-4inch-...-/231396930279
with 12 x 5W LEDs and a wide range of input voltages?

I would expect them to be at full brightness at any voltage in the specified input range since dimming is not normally a feature required in driving lights. If that's true, then it's probably got a DC/DC converter (not to be confused with DC/DC chargers from other threads!) that will take any voltage from 9-32V and produce twelve CC streams, one for each LED. And if all that's true, then the input current might be quite choppy.

What are the specs on your power meter? I'm wondering if it could be a sampling issue caused by a choppy current signal going into the light. To rule that out, you could wire a 0.1R 10W resistor in series with the light, and put a true RMS volt meter across that. Or, if your true RMS meter is good for ~10A stick it in series with the light and see what it reads.

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Bingo, that's the one.

Here's the power meter http://www.ebay.com.au/itm/Digital-L...kAAOSwnDZT~DG1

[dBC Member Find all posts View Profile Close dBC]

Bingo, that's the one.

Here's the power meter http://www.ebay.com.au/itm/Digital-L...kAAOSwnDZT~DG1

Hard to say from those specs, other than it is meant for DC signals, and depending on how poorly designed the light's power supply is, it may be a long way from that, as described above. In that case it comes down to meter bandwidth Vs the shape of the current signal. This bit:

"Use DSP to increase ADC resolution" makes me think they may be doing some dithering and oversampling, which as they say is great for increasing resolution, but always at the expense of bandwidth. It's a technique best used on very slow changing signals.

If you can borrow a quality true-RMS multimeter that's good for 10A on the current setting, you may get quite a different reading.

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My multimeter is similar to this https://www.jaycar.com.au/automotive...ickup/p/QM1444

Looks like this

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

amts,

As I wrote it is common practice for shonky ebay sellers etc to use specify the theoretical and not the real power output, it is deceptive advertising used to suck in those not familiar with the practice.

If your unhappy with your purchase go back to the seller and complain that your measurements show they do not consume the claimed 60W, or you could also start a dispute for not as described as they have not indicated it is theoretical power. They will then most likely offer you a partial refund or begrudgingly accept a return if you insists on a refund, problem is it will probably cost you more than their worth to ship them back.