LEDs simplified? Layperson's terms please!

[deniseO30]

mostly dome light installs. I like the 36 led cards with the socket wired.

Led's save power..

Do they provide enough light?

watts..

Lumen loomens lumans.. lumininsms

I'm looking at doing all the dome lights eventually. If I turn on all 7 dome lights and they all have at least 15 watt bulbs.. that's around 9-10 amps.. add the anchor light radio

But let's not make this about how to figure out amp hours.

[Gladrags1]

Denise:

I just struggled with that question myself. The cabin lights aboard Mandolin are all halogen which puts out a bright light. We needed to add a light in the galley over the stove and were trying to decide between a dc powered fluorescent, incandescent dome light, and Dr Mars LED (3 watt) dome light. To compare light output you look at lumens. But there really is not a good correlation between these 3 types to really compare them and I was disappointed in the industry's ability to adequately answer that question. West Marine has a good display of several dome lights that are connected so you can see the brightness of the LED as compared to the incandescent but there is no fluorescent connected. Also, looking at the displays in the light of a well lite store makes it hard to compare. I ended up buying the LED dome light. It is the brightest of the LED's but it really didn't provide the light I was hoping for. I guess you can say that I am underwhelmed. I don't know if I would be happier with the flourescent. I was looking for a light that provided an area of light that lit up the stove and galley work area in a bright glow. Now, I haven't quite seen my light on at night in an otherwise dark boat so I might be more impressed in I did. The halogens are significantly brighter. So... That is my experience. I am sorry as I don't think I gave you a satisfactory answer to your question and my raise more questions than answers but I thought you could have the benefit of my experience. I am going to the boat this weekend and will hopefully see the cabin at night with the lights on and get a better picture of how that LED does in full darkness.

Tod

[MacGyverRI]

I just replaced / rewired new lights in a customers 34' Silverton.

The 18"? 12 volt fluorescent light from WestMarine is really really bright and went over the dinette w/ light to spare, like being in a house. I also put a Puck 4red/4white combo LED's next to it for mood lighting.

The combo WM 4 white/4 red LED puck type lights are useable but dim, more for mood or non tripping lighting at best. 2, 8-12+ LED's would be great stand alone but very sterile looking light.

The smaller WM fluorescent light (12"?) gives good light over the galley/sink area and a Puck combo LED went there also.


FWIW,
Any replacement bulbs for standard socket Auto/Boat fixtures should have at least 15-20+ LED's on them to get really good lighting.

You will get "pure white lighting" (sterile) w/ most rather than cool or warm white.

"Lumens" (brightness) are used because the LED's can't really be rated in "degrees Kelvin"

i.e. warm white 3000+ DK
Cool white 4500+ DK
Grow lights/Natural sunlight bulbs 6500+ DK (these give the sunlight spectrum, like a makeup mirror)
Reef Tank (fish/corals) 7000+ DK

A few EBay sellers had good prices on #1004 LED (common for boats) bulbs.

[bljones]

Here's a good comparison, provided by MaineSail:

http://www.sailnet.com/forums/gear-m...omparison.html

[Gladrags1]

Thanks MacGyver. That was very helpful! Thank you bljones for the link to Maine Sails.

Tod

[FarCry]

Originally Posted by MacGyverRI

I just replaced / rewired new lights in a customers 34' Silverton.

The 18"? 12 volt fluorescent light from WestMarine is really really bright and went over the dinette w/ light to spare, like being in a house. I also put a Puck 4red/4white combo LED's next to it for mood lighting.

The combo WM 4 white/4 red LED puck type lights are useable but dim, more for mood or non tripping lighting at best. 2, 8-12+ LED's would be great stand alone but very sterile looking light.

The smaller WM fluorescent light (12"?) gives good light over the galley/sink area and a Puck combo LED went there also.


FWIW,
Any replacement bulbs for standard socket Auto/Boat fixtures should have at least 15-20+ LED's on them to get really good lighting.

You will get "pure white lighting" (sterile) w/ most rather than cool or warm white.

"Lumens" (brightness) are used because the LED's can't really be rated in "degrees Kelvin"

i.e. warm white 3000+ DK
Cool white 4500+ DK
Grow lights/Natural sunlight bulbs 6500+ DK (these give the sunlight spectrum, like a makeup mirror)
Reef Tank (fish/corals) 7000+ DK

A few EBay sellers had good prices on #1004 LED (common for boats) bulbs.

Denise the quote above gives some specific suggestions and Mainesail provided an excellent report as usual.

Besides the color of the light (Kelvin Scale) and the brightness of the light (lumens) you have a third variable to try and consider as well, that being how the light is dispersed from the fixture. For example, some fixtures may provide some sort of reflector that partially focuses the light, think typical flashlight (Maglight). The Maglight is putting out the same number of lumens, but depending on how it is focused, the amount of light reaching a specific point can vary wildly. The reason I want you to consider this is, for overhead lighting to illuminate the sole, you may want a more open spread of light. Over a sink, stove, or table you may want something more condensed to control the spread and focus the light more on the area of where you need it. That brings us to the next term, foot candles, which is how much light is actually getting to a specific area. Two LED lights rated for the same lumens, may have very different footcandle ratings when directly compared at a set distance. Mainesail did a good job to eliminate the variables in his report and made it easy to see the difference in beam spread.

I would disagree that 15-20 Leds are necessary to provide good light in a replacement bulb. Mast makes some decent LEDs that replace a halogen lamp that use 4-5 and provide a very nice, even, light that isn't too far from a standard incandescent lamp in color. At least to my eyes and those who've been aboard.

Good luck and remember when shopping LEDs, cheaper lights are frequently not built to handle the voltage variables that a typical marine 12v system encounters as well as ones that cost more.

[erps]

I bought a cheap LED reading lamp that worked great at 12.5 volts and sucked below 12.2 volts. Is there a rating for the voltage/performance curve?

[hellosailor]

"Do they provide enough light? "
"Enough" is a totally subjective judgement, you'll have to buy one and try it out to see.
Lumens are the objective comparison, you can look up the bulb type in your existing cabin lights online (i.e. "1156 bulb lumens") to find out the output of the bulbs you have now. That's not a perfect comparison, because a filament bulb puts out light all over and relies on the fixture to reflect and focus it, while the LED panel is putting out light "that way" only, so the light is more concentrated to begin with.
Buy just one or two to try in a place where you don't need a lot of light, or buy them from someplace that will let you return them.

[JimsCAL]

My Cal 33-2 has a bunch of Perko dome lights and 2 reading lights, all using bayonnet type bulbs. As a trial last spring, I replaced one of the dome bulbs with an Imtra LED replacement. It's nine surface mount LEDs on a board and wire connecting to a bayonnet connector. Takes about 2 minutes to take the cover off, remove the bulb, stick in the LED unit and put the cover back. Light color and brightness seems the same as the incandescent bulb. Based how well the unit worked last year, I replaced 2 more domes and the 2 reading lights with Imtra units this month. They are $16-19 each at defender.com.

[Maine Sail]

Originally Posted by FarCry

I would disagree that 15-20 Leds are necessary to provide good light in a replacement bulb. Mast makes some decent LEDs that replace a halogen lamp that use 4-5 and provide a very nice, even, light that isn't too far from a standard incandescent lamp in color. At least to my eyes and those who've been aboard.

You're right you can not buy LED's by the number of emitters. The absolute brightest, and widest, bulb I have tested thus far is the single emitter Sensibulb. With just ONE LED this bulb is brighter and any other LED I have tried.

Yes it is brighter than some with 20+ LEDS..