Thread: Led light bar

Correct... BUT... And here is the BUT...

Modern vehicles have 120Amp minimum alternators.. Later still have over 150Amp alternators...

Running at 75% wont hurt these beasts... After all, when winching the poor buggers are flat out

I've never killed an alternator from aux lighting requirements...

Now...

Jon, I know you ran 4 aux lights on your Rangie... 4x100w minimum and the alternator ran fine...

Thats 33.33a @ 12.0v or around 29.9a @ charging voltage...

A pair of IPF "Filament" lights pulls 130w x 2 = 260w -> 21.67a @ 12v
A pair of Fyrlyts "Xenophot filament" pulls 150w x 2 = 300w -> 25a @ 12v
A pair of 50w input HIDs pulls 100w -> 8.33a @ 12v

A decent improvement it would seem...

But is it? What do you get for your dollar???

Well............ Lets start with HID

35W (input) x 80% efficiency ballast = 28W to lamp x ~85 lumen / watt globe output = 2380 lumen (35x2=70 -> 5.8a @12v)
50W input x 80% ballast efficiency = 40W to lamp x ~85 Lumen / watts (China) = 3400 Lumen(50x2=100 -> 8.33a @12v)
70W input x 80% ballast efficiency = 56W to lamp x ~85 Lumen / watts (China) = 4760 Lumen(70x2=140 -> 11.6a @12v)

This is FACT.... Has been proven and tested

Now here's the kicker.... This is when the HID bulb is BRAND NEW...

HID’s will lose 25-30% of their output per watt over the life of the bulb and also a shift in colour rendering.
This occurs rapidly in the first few hours and then continues.
This is why in prestige cars with HIDs in OEM fitments, must be replaced in pairs. (To maintain same intensity / colour)

The Xenophot style globes retain colour rendering and output for the entire life of the bulb...

And due to Osram working closely with Fyrlyt they have produced a bulb with a genuine output of 5000 lumen each bulb...

Also consider reflector design and scatter, focus, glare etc... (HIDs produce noticeable glare), poor cut off etc, and cost (including light units, HID kits and TCO) and you dont get a lot for your money.

Consider that if you go "Branded" HID you pay a premium for such outputs... An uprated (if required) alternator is cheap!!!

A pair of 150w has been running on a mates FJ40 (55amp alternator) for over 2 years now, he's a professional shooter (cull) for the Government and shoots a lot at night. This vehicle has had NO issues... Which confirms older vehicles are well in capability of running such current draw.

A modern alternator barely breaks a sweat

What you need (as a driver) is clear, usable light with minimal Glare. Where you need it, when you need it -and not waiting for it to come back up to temp or intensity!!!!

HIDs fail at this, all for a small power saving....

Originally Posted by skuilnaam

I've never killed an alternator from aux lighting requirements...

Now...

Jon, I know you ran 4 aux lights on your Rangie... 4x100w minimum and the alternator ran fine...

I have. My Rangie alternator died, quite possibly with the extra 400w load.

4 x 35w HID is a much smaller load (140w extra vs 400w extra).

LED vs old style filament? I do not think curent draw is important but you get a lot more light from LEDs per watt. Smaller cables needed. Each to their own but the light temperature is very different and takes getting used to. I found this when I went from halogen to LED for my caving cap lamp.

Interesting to note, Bosch Long Haul Truck Alternator
is only 160 Amps. And those things are covered with lights.

Heavy Duty Bosch Long Haul Alternators

Originally Posted by CaverD3

LED vs old style filament? I do not think curent draw is important but you get a lot more light from LEDs per watt. Smaller cables needed. Each to their own but the light temperature is very different and takes getting used to. I found this when I went from halogen to LED for my caving cap lamp.

Got a little off topic....

Yes LED is a lot different....

Optimum setup (as I acknowledged earlier) is:

2 decent lights for distance + LED Bar for flooding the immediate area.

Originally Posted by BigJon

I have. My Rangie alternator died, quite possibly with the extra 400w load.

4 x 35w HID is a much smaller load (140w extra vs 400w extra).

My point exactly.... However, your alternator was most likely going anyway being an old Rangie unit

Old Halogen setup: 400w = 33.33a @ 12v

140w input = 11.67a @ 12v

producting a grand total (when new) of 2380x4 = 9520 lumen

give them a month of use and you reduce output by 20% (and they get 'bluer') = 9520 * 0.8 = 7616 lumen

Conversely:

2 x 150w units (300w) = 25a @ 12v producing 10,000 lumen
This will be produced at the same intensity and colour temperature for the life of the unit.

This is 25% less current than 4x 100w conventional (H3) spotlights.


Its also ~25% more light than HID once they have burnt in.

Well within the scope of an early model alternator

Jon, how old was your alternator? What else did you run? How often?

Back in the days of the Discovery 2's we had 2 x TD5s do alternators in under 15,000km from new (warranty) and running no accessories / modifications at the time.

Both have since ran a large array of lights (min 4x100w) with no issues.

And a TD5 pulls a lot more power than an old Rangie...

In interest to it, I'll throw a Fluke on the TD5 and the TDV6 and measure them running the vehicle in its normal mode... I'd suggest the normal operating draw to be very low.... Even on the electrically complex D4 (will cycle compressor too to see what load changes).

Sorry, but the brain washing of the superior "HID" is not there.

In another thread I will post on colour spectrum vs glare vs pupil behaviour...

Once you get into lighting (LEDs, HID, Halogen etc) and start really understanding the nuts and bolts of it all its quite amazing.
Add in the mechanics of the human eye, our perception of light and how we see it all starts to bring the "big picture" together....

Side note: A 200amp Alternator for a Land Rover V8 is no more than $400.00 and will power the QE2

Originally Posted by skuilnaam

2 x 150w units (300w)

Slightly off topic, but my experience with 130w bulbs is that they last for a matter of hours, and not many at that. I can only think 150w bulbs would have an even shorter life span.
100w bulbs last quite well. I have replaced one HID "bulb" in 7 years with a lot of night time driving.