240w LED lightbar on VS ecotec

[Cpt Awesome]

Sup ppl. I'm intending to drive to Sydney soon from Perth and I want to put an LED lightbar on a roof rack for some extra light for the mostly country driving. So the question is Should my 100amp alternator be able to handle the 240watt draw the lightbar demands?..... Aswell as the four 100watt HID spotties I already got on and the two 100/130watt dual filament halogens in the low beam reflector???

I suppose to simplify I want to pull 900watts off the battery just to run lights and I just want to know if I'm going to have to upgrade anything from the stock electrical system

 

[Not_An_Abba_Fan]

What amps does it all pull, wattage is irrelevant really, it's the amperage you need to know.

 

[Cpt Awesome]

Well am I right in saying
power = current x voltage
So 900/12 = 75 amps?

 

[Cpt Awesome]

That's what is making me think, how many amps does the car pull while just running on its necessities?

 

[Not_An_Abba_Fan]

power/voltage = amps, so yes, 75 amps. The standard alternator is 85 amp, so it should be fine. Just run heavy cable to your light bar so there is less resistance along it.

 

[Big-Al]

Invest in a clamp meter, it's the only way to check exactly how much you're drawing and how much you are producing. Your alternator won't be producing 100 amps and low cruising RPM.

 

[Cpt Awesome]

Coz what I'm thinking Is that I'm pulling 75amps just to run lights, how much current does the car take to run? Will that push the alternator over the limit? How much ya reckon for a clamp meter?

 

[Jxfwsf]

Given all the other electronics, ecu + sensors, trans (if auto), stereo, coils, heater fan, wipers etc etc then adding all that extra lighting then I'd say yes you will have issues if you need to use everything at once, probably won't kill the alternator but it'll most likely burn out the stock main charging wire or you'll end up with a flat battery while driving.

 

[Cpt Awesome]

Yes it is an auto. I've got a pretty large charge wire good for 160amp(coz it's sub cable!) but yeh I talked with auto spark and they reckon the largest alternator they can get me is only an extra 10amp over the one I already have (which is 100amp). But I swear I seen 140amp alternators on the vs that dudes use who have massive sound systems!? Also dya reckon id need a deep cycle battery?

Cheers for the input!

 

[MuckUte]

You should only need a couple of GOOD spotlights, not just high wattage and they will most likely cost less than a bigger alternator and a new battery. I had 2 Lightforce 204 Blitz spottys in my bullbar and 4 bull lights on the roll bar. All were 100W but with the Lightforce lights on I could hardly tell when the other 4 were turned on and off. Spot/driving/head lights above 1500mm high are illegal it's just that in some areas it is more strictly enforced than others. The other issue with lights above your eye level is that it is easy to dazzle oncoming drivers as the lights will shine over crests that you can't see over