LED fog light add-on wattage ques.

[BigM]

looking to add some led fog lights to the frt. crash bar underneath.A dead spot in light when I turn and live around deer, etc. On back roads. Led  Bar lights approx. 8 inch. long. by around 1 1/2 thick. the quest. is.
 I can get 18 watt, 36 watt and 54 watt. All have about the same burn temp. But higher is brighter. Which do you think would be best. Would the 54watt be too much draw etc. I do see that the headlight is around 55 watt. I'm not a electrician so new to me. Will be running a relay and would wiring from headlight circuit work?

[Grandpot]

54W is only 4.5A.  Not much draw at all.

[sandy]

On my old Valk, I had 4 halogen lights totaling 112 watts plus the headlight. Never had any electrical problems.

[WintrSol]

Yes, you can use the headlight circuit to turn a relay on; you should put a 10A fuse in the line from the relay power contact to the battery.

[gordonv]

Basically you can do whatever you want to do.

Doesn't the lights come with a fuse in the wire? Then it can handle the load.

If you wire, then you do your basic math to figure out the Amps. Ohms Law, I think it is (I'm sure someone will correct) to come to a finding.

Amps = Watts/Volt

[John Schmidt]

You're always advised to run any extra lamps on a circuit totally separate from the headlight circuit. If that circuit goes south on you, you still have lights to get home by.

[Blackduck]

Unless you have a lot of other accessories that is nothing.
I have run a pair of 100 Watt driving lights on both my Valks.
As suggested run the power from the battery to a relay then use either the headlight circuit or separate switch to trigger the relay. If there is a legal requirement run the trigger off the high beam side of the headlight and still run a separate switch. This will drop the auxiliary lights when going to low beam or allow you to turn them off as needed.
Cheers Steve

[MarkT]

I modified my H4 spots circuit to provide backup power in the event the main headlight circuit fails.  Previously it depended on the blu/wh OEM line to the Hi-Lo sw to trigger it's relays, so it would go off with the starter button.  Now I've added a 3-pos selector sw to select that same blu/wh line, or if it fails, sw to the taillight brown circuit. If that source is selected, it will not shut the lights off with the starter - but I will have lights to get home. The same could be applied to your simpler circuit, if you don't want to implement my more complex one. See the "select sw" part, upper right in this schematic. You would use a 3-pos sw, "on-off-on", with the center pin to the trigger #85 or 86 (the other to grnd) of your relay, and the 2 outer pins, brown wire and blu/wh wire (or blu wire if you want it to come on with hi-beam).  Those wires are all in the bucket. Of course run a separate wire, 12 gauge would be perfect, from the battery thru a fuse to the relay power pin #30. Output to the spots would be pin 87 on the relay.  Note in this circuit the diode between R1 & R2 which prevents backfeed from the spots circuit into the main.  In case the OEM headlight circuit has a short, blew a fuse, and would also cause the spots circuit to blow a fuse thru the same short. (Also prevents backfeed in normal use.)

BTW I've never had a headlight circuit failure in a quarter million miles on my Hondas.  I have lost headlight bulbs, and once burned out a bulb socket. But that doesn't mean it couldn't happen.

[BigM]

Found some neat lights. Made by Cirius. Mount to the crash bars. More than I want to spend , drill, and tap. But would def. be out of the way. Flush mount on bars.