Voltage regulator question

[kevdog3019]

On my Lario, wondering how much heat is generated by the voltage regulator?  Wanting to paint it and not sure if this is a good idea if there's a need for heat dissipation. Lets say you?
Thanks

[Triple Jim]

I have a PDF file of a NASA test report that says that if the paint is less than 0.004" thick, it will help heat transfer.  More than that, it will hinder it.  Keep the paint thin and it'll be fine.  I'll post a link to the report if you're masochistic.

[Moto Fugazzi]

What color did you plan on painting it? Black will absorb heat. I would think as long as there's air circulation, you should be fine.
Why not just give it a good scrubbing and keep it the way it should be?
Ken

[Old Jock]

Which alternator does the Lario have (pardon my ignorance)?

If the alternator is Saprisa or the like, permanent magnet then its going to get hot, if its Bosch electromagnet then not so hot.

Just saying

[kevdog3019]

Thanks. It's a Bosch system. I painted it black (Plastidip) which I can remove if need be.  I don't like the idea it's surrounded by "rubber" but I guess I'll find out...

I did it because it's a sore thumb in light grey and silver sitting to the outside of the battery area where my bike is now naked.


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[Kiwi_Roy]

A black object radiates more heat than a shiny one, Physics 101

[charlie b]

It can also absorb more heat :)

[Kiwi_Roy]

It can also absorb more heat :)

That's right, but I assume the regulator is hotter than the surroundings

[Triple Jim]

"Color" to heat is not necessarily the same as colors we see.  Black absorbs more sunlight than white, so it gets hotter in sunlight than white, but there is a lot of visible energy in sunlight.  To a hot regulator, the wavelengths emitted are much longer, and well into the infrared region.  Our eyes can't see that frequency, and "black" in that range may look white to us, or pink, or green, no telling.  You'd have to look up the emissivity of the particular coating at that frequency to know how "black" it is.

Keep the paint or other coating thin if you don't want to reduce cooling.

[Wayne Orwig]

A black object radiates more heat than a shiny one, Physics 101

Someone will run with a simple statement like that and go with it literally.
If I wrap the silver aluminum cylinders on my EV with a layer of black cardboard, it will not run cooler.
Just the same. If I spray a heavy layer of black tar on the cylinders, it will not run cooler.
It has to be a THIN layer of the PROPER TYPE of black paint to not make matters worse.

[kevdog3019]

Someone will run with a simple statement like that and go with it literally.
If I wrap the silver aluminum cylinders on my EV with a layer of black cardboard, it will not run cooler.
Just the same. If I spray a heavy layer of black tar on the cylinders, it will not run cooler.
It has to be a THIN layer of the PROPER TYPE of black paint to not make matters worse.

Yes... bottom line is I'm insulating this thing.  I agree with Wayne that I'm not helping it out.  I'm looking for someone that knows to say "hey man, what are you doing...this thing is living on the edge as is and you put a coat on it?"  I do have it out in the wind instead of undercover as it is stock, so there's that. Am I living on the edge? Is it inches from flames with some paint on it? These things seem to live nice long lives.

[Triple Jim]

Is it inches from flames with some paint on it?

I would not do something to a heat generating electrical component that I know would make it run hotter.  As far as "some paint", I posted above what the NASA test report says.

[Kiwi_Roy]

Someone will run with a simple statement like that and go with it literally.
If I wrap the silver aluminum cylinders on my EV with a layer of black cardboard, it will not run cooler.
Just the same. If I spray a heavy layer of black tar on the cylinders, it will not run cooler.
It has to be a THIN layer of the PROPER TYPE of black paint to not make matters worse.

Ok then, bolt it to a big black finned heatsink with some heatsink compound in between.
Or even better move it to the front of the bike where it gets splashed by rain and road salt like on the spine framed bikes. Actually I share your concern with regulator overheat, when I moved the one on my V11 Sport up under the tank I bolted to a fairly large Aluminium plate.

So a thin layer of flat black paint then?
Take two identical tin cans, paint one with the black of choice, leave one shiny then fill both with boiling water. see which one cools first and fly with it ;D