Light Bar Amp Draw

[PeeBee]

I am confused. I have bought a 700w lightbar, running on circa 13 Volts, which equates to 53 amps (W=VA), but the kit is supplied with 'wieny' small diameter cable and a 40amp fuse.

Is there some sort of conversion factor for LED light bars that I am not understanding? I am yet to check the volt drop - will do tomorrow, but i am think I need around a 16 - 25mm2 cable on pos and neg to get the best out of these lights?

Of course since they claim the lights to be able to run over voltages up to circa 30V, i am wondering if this is where the reduced amperage is assumed, even though they are sold for 12v systems - HELP PLS, totally baffled.
Phil

[MudRunnerTD]

Have you got a link or spec sheet on the light bar. 700w seems extraordinary

[Mike02Ti]

Voltage amps and wattage are all relative to each other via ohms law.
So if it is 700w at 12vdc it will be 58.33amps
So based on that i would go around 8 guage wiring depending on how long your power run is. At least that gives you some headroom regarding voltage drop etc
Im guessing its a 52" light bar?


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[Clunk]

This PDF may help you

[Clunk]

another one on the redarc site might be better

https://www.redarc.com.au/images/upl..._worksheet.pdf

[Ben-e-boy]

The problem with alot of automotive multi-volt (generally 9-36v) LED lighting manufacturers, is that the advertised specs are based on the highest input voltage. It helps with advertising, and is misleading but not a lie.

If this is the case, which I believe it is. It will not be a 700w unit @12v. But a bit more info on the the lightbar is needed to determine if I am on the right track or not.

[PeeBee]

Have you got a link or spec sheet on the light bar. 700w seems extraordinary

Check out ebay, about $110 from memory. 100 x 7w cree's

[PeeBee]

Voltage amps and wattage are all relative to each other via ohms law.
So if it is 700w at 12vdc it will be 58.33amps
So based on that i would go around 8 guage wiring depending on how long your power run is. At least that gives you some headroom regarding voltage drop etc
Im guessing its a 52" light bar?

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Yes 52" thanks. Just working on the mounts as the roofrack is curved on the ends.

[PeeBee]

The problem with alot of automotive multi-volt (generally 9-36v) LED lighting manufacturers, is that the advertised specs are based on the highest input voltage. It helps with advertising, and is misleading but not a lie.

If this is the case, which I believe it is. It will not be a 700w unit @12v. But a bit more info on the the lightbar is needed to determine if I am on the right track or not.

its on ebay, 52" 700w 100 x 7w cree, about $110 from memory.

[Turtle_au]

700w @ 30V = 23.3 Amps - not counting the power used by the LED driver.
If the unit is current limited then 23.3 Amps @ 12V = 279w

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