High Output Alternators

[2.2 Straight six]

I will at some time be buying a truck (once i've moved) which will most likely be an '01-03 F-150. i want to add spotlights to both the front and also on the roof, as well as a lightbar. i figure to run between 6 and 8 spotlight and also a lightbar (although it'll rarley be used) i'd need a more powerful alternator to cope with the increased power demand.

what i'd like to know is firstly, will i need a higher output alternator?

also, what kind of output would i need (amperage)?

and finally, if i install a higher-output alternator, will that have any negative effect on the truck when the lights aren't being used? will it cause fuses to blow or cause circuit damage?

Thanks,
Chris.

[UncleBob]

what will be the total amps of the lights you use? Gotta know that before you can debate on what alternator will work.

There are no disadvantages, assuming that the wire gauges are large enough to handle the added capacity of the alternator. Fortunately, its quite easy to upgrade the alt wire if necessary.

[2.2 Straight six]

since resistors are the only 100% effiecent devices for energy transfer, and that's all a bulbs is, i'm going to say it's safe to assume that light output is pretty much equal to current demand. (that is right, isn't it?)

i'll have a look and work it out.

[UncleBob]

not sure what you're getting at, X candlelight power = X watts? Not even close. There are many diferent types of lights that have different levels of efficiency/output per watt.

How can you possibly answer this question if you don't even know what lights, and how many, you plan on using?? Thats like asking how hard it would be to make 200hp with an engine that has unknown cc's and cylinders.

[Moppie]

So, Iv got this neck, and I want to make it red.

How much hp will it have, and how much current will my mullet draw?

[KiwiBacon]

Originally Posted by 2.2 Straight six

also, what kind of output would i need (amperage)?

Add up the watts of all of your devices (lights, stereo, fans, EFI etc) and divide by 12 (for a 12v system) to give you a rough idea of amperage.

Then you want to find the rating of the current alternator and compare.


IMO too much light is stupid. You end up blinded by the reflection off roadside signs and going to dip makes it hard for your eyes to adjust.

[GreyGoose006]

if it were me, i would figure out the amps needed, then err on the higher side because nobody likes being stranded due to a dead battery...
also, how well and when the alternator is producing power is a consideration too.
a lot of police cars are equipped with alternators that can supply ~80% of total power at idle. they are more expensive, but better (IMO)

[2.2 Straight six]

Originally Posted by UncleBob

not sure what you're getting at, X candlelight power = X watts? Not even close. There are many diferent types of lights that have different levels of efficiency/output per watt.

How can you possibly answer this question if you don't even know what lights, and how many, you plan on using?? Thats like asking how hard it would be to make 200hp with an engine that has unknown cc's and cylinders.

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

[KiwiBacon]

Originally Posted by 2.2 Straight six

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

Watts is power consumption, not light output.
Light output varies hugely when comparing lights of the same power consumption.

[UncleBob]

Originally Posted by 2.2 Straight six

i'm looking at various lights, and choosing the ones i want.

what i was asking was is it correct that power demand is equal to light output.

ie: 8 lights x 100w (100w per light) = 800w (i think this bit is right)

but then is 800w the right demand, or is there something else i've missed out that needs to be accounted in.

to put this in perspective: 800w = 67 amps. A stock F150 has 2 stock alternator options, 95 and 115 amps. Now its extremely unlikely the system amperage is only 30 amps, but of course, it depends what you have turned on, such as headlights, blower motor ect.

If you cut it down to 6 100w lights, and used the 115amp alternator, and kept an eye on a volt meter, being careful of what accessories you have on when all the lights are on, you'd probably be fine.

But there's probably upgrade options also

[2.2 Straight six]

i'm still trying to find the "right" lights, haven't made a final decision yet.

i'm thinking Hella, i know they're good. any other reccomendations?

also, anyone know a good brand for high-output alternators? i'm struggling to find one.

[2.2 Straight six]

Originally Posted by Another Forum

According to Ford literature, the 1997 F-150 4x4's available in the United States all have 130-amp alternators.

might not need to replace it..

[turtlecrxsi]

Yes... you may not even need to replace it. Also, 100w lights are a bit over the top IMO. Most halogen head light bulbs run at 55w and high beams run at 65w. Obviously you want recreational lighting. Perhaps a couple of 100w lights and a couple of 65-80w lights. My suggestion would be to go look at trucks that already have lights on them and see what they are using. Where I live there are more pick up trucks than probably most anywhere (South Carolina) and everybody has mods... even work trucks are lifted with tires and lights... and yes, the ever present tool box in the back as well. If you research more in depth for which would be the most efficient lights to use let me know because I'm probably going to install some nice fog/driving lights on my Jeep.

[2.2 Straight six]

Originally Posted by turtlecrxsi

If you research more in depth for which would be the most efficient lights to use let me know because I'm probably going to install some nice fog/driving lights on my Jeep.

the 100w was just an example number for ease of showing stuff in calculations.

i'm going to carry on looking into this, i can't offer an post-usage info for a while because the earliest i'll be getting a truck is like august/september (if then, maybe later) and i doubt i'll be getting lights on it for a while after i get it. (money being the deciding factor.)

[turtlecrxsi]

Oh yeah I know. I meant if you come across some sweet examples of mounted lights on trucks or SUVs post em' up or send a PM. I've been looking a little as well at the Hella lights with the mesh guard around them...