LEDs getting hot?

Quint4

Quint4

Well-Known Member
TECHNICAL Contributor
Oct 6, 2006
6,750
NC
Boat Info
CY 3375
Engines
7.4 MPI twin
I replaced all the interior halogen bulbs with G4 LEDs. They look great but get very hot? I checked them with my IR gun and got a reading of 209 F.

Hell my "mini heater" halogens bulbs were 220 F.

I am disapointed as I wanted to rid my fixtures of heat.

Am I missing something? Do I need a resistor in the circuit?

Here is the bulb I am using.

IMG_0479.jpg

IMG_0480.jpg
 
The biggest killer of LEDs is heat, a little misunderstood thing with them. By that I mean heat reduces their light output and lifespan. And yes they burn hot. Particularly if the manufacturer wants to increase the light output (brightness) cheaply. They achieve this by driving the LED hard. Thus the initial brightness is high, but the result is heat and depending how hard they drive it lower life.

Hence if you look at LED work lamps, driving lamps etc, you will notice the good quality ones are in Aluminium houses with fairly large fins on them, this is to dissipate the heat.

Maybe have a fiidle with a resistor in the circuit, or a voltage regulator, if you can drop the voltage down to the lights by even a 1V you should reduce the light output only marginally but possibly reduce the heat.

Unfortunatley the LED replacements in the picture has no Heat Sink so they are going to burn hot.
 
Thanks guys
 
what about installing a 12VDC dimmer control so you can vary the voltage and amount of light output according to the need at the time....i use 3 of these LED dimmer controls on some LED light strips in my boat and they work well....

cliff
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I put 25 LEDs in my interior fixtures. Two of the circuits are on dimmers.

They all get hot as previously described.
 
Quint4 said:
I put 25 LEDs in my interior fixtures. Two of the circuits are on dimmers.

They all get hot as previously described.
Click to expand...

that does sound unusual...i have LED accent lights in the cabin and cockpit as well as LED strips in the cabin and under the swim platform....even with the dimmer switches turned all the way up none of the bulbs get hot, not even warm....all stay cool to the touch....most likely the LED bulbs you are using are high output bulbs....

cliff
 
Check out marinebeam.com - they have some nasty videos of what happens when a cheap LED bulb gets too hot. I replaced all my cabin's halogens/incandescent with bulbs from marinebeam and none of them get more than warm to the touch...and they're brighter.

To get technical, some replacement LEDs use a linear circuit to regulate the current going to the LEDs. These are very inefficient and can run hot. (The linear regulator is usually the part that gets hot.)

The best ones use a switching circuit which are much more efficient and run cooler.

Worse case scenario is no regulator, just a dropping resistor which is indicated by varying intensity on the LED as battery loads change or engines are started or stopped. Judging by the pictures you posted this is what you have. More than likely, the heat is generated by the dropping resistor although if the LEDs are being over-driven, they can get hot as well.
 
FWIW, I repaced the reading lamp bulbs with wedge base LEDs from Superbright and they do not get hot.
 
I think my $4 LED bulbs were not such a bargain.
 
I have been emailing Jeff from Marinebeam.com. He seems to know what he is talking about.

Here is an excerpt from his response:

"Yes, those are resistive LED bulbs. They have a discrete rectifier rather than a proper 4-diode bridge, and current controlled not even by a proper ballast resistor, but strictly by the total voltage drop of the whole string of LEDs themselves.

What is really funny is that the board has a place for a constant current IC, an inductor, and a capacitor. But they left all those out, and just bridged the IC pads together, and stuck a small SMD resistor in the spot where the inductor (L1) is supposed to go. They left the sense resistor in its correct place, though it will do nothing, as it is only there to give voltage drop feedback the IC for current control.

I hope these were free, as they are the bottom of the Chinese barrel. They basically took what could have been a decent bulb and jury rigged it to turn it into a resistive cluster."
 
I have replaced all of my 12V bulbs with LEDs from the following vendors. Prices were in the $5-$15 range per bulb, depending on the bulb size/type. They all stay cool to the touch:

MarineBeam
SuperBrightLEDs
LEDlight
LEDwholesalers

I don't recommend any one of these four vendors over the other. They all seem to have good stuff.
 
I have the same style bulbs from superbright and none get hot, even though they're running off 24V.

Paul
 
This is a problem when LED's are not designed correctly. There is a two part heat dissipating product that can be used to help cool the LED's. This should only be used with a properly designed LED unit though.
 
I have emailed the vendor requesting a refund.

I plan to buy 25 G4s from Marinebeam.com and end this " you get what you pay for" saga.

Be wary of cheap LEDs, I think they are a fire hazard (actually there have been boat fires attributed to cheap LEDs).
 
Quint4 said:
I have emailed the vendor requesting a refund.

I plan to buy 25 G4s from Marinebeam.com and end this " you get what you pay for" saga.

Be wary of cheap LEDs, I think they are a fire hazard (actually there have been boat fires attributed to cheap LEDs).
Click to expand...

no one can blame you from trying to be 'economical' on these type things as most of us do the same....but sometimes the most 'economocal' solution is not the best....been there soooo many times myself.....

good luck....

cliff
 
Quint4 said:
I have emailed the vendor requesting a refund.

I plan to buy 25 G4s from Marinebeam.com and end this " you get what you pay for" saga.

Be wary of cheap LEDs, I think they are a fire hazard (actually there have been boat fires attributed to cheap LEDs).
Click to expand...

Who did you get them from? and keep us posted on their refund process.

MM
 
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