Use of 10-30V DC LED bulbs

[yachtee]

Hello everyone,

Hope, someone can advise me regarding the following problem.

Some time ago I changed 24 V DC G4 halogen bulbs to 10-30 VDC/ 11-18 VAC G4 LED bulbs. The input voltage is nominally 24VDC, but in fact approx 27-28 V, because the service batteries are being constantly charged.
After some time (about 1 month, the bulbs were ON only at night) the bulbs started to fail, now most of them are gone. The electronic part on the back of the bulb was partly black and smelled burnt.

Does it mean that 10-30V DC bulbs are not really designed to work all the time with 24VDC input and I have to install something to decrease the voltage to 12VDC? Or shall I try first bulbs of another maker?

I havenn't seen anywhere specifically 24VDC bulbs. All of them are either 12VDC or 10-30VDC.

Thanks and regards.

 

[snakebite]

brand? model? pics?
a lot of these conversion bulbs are pure junk.
probably a cheap resistor setup.
buck converters run cooler at high voltages.

 

[broadgage]

There is indeed a lot of cheap rubbish out there, I suspect defective manufacture.
I would expect that a bulb stated to work from 10 volts to 30 volts should be fine at a continuous 28 volts.
A 24 volt nominal boat or other vehicle would be the most likely application and as you point out will be about 27 to 28 volts when the engine is running and the battery is charging.

I would try another make of the same type of product.

I do not believe that dropping the voltage would help. Even the most basic bulb that works over such a voltage range must incorporate a buck converter and the input current would therefore be less at the higher voltage.

When retrofitting LED bulbs of unknown quality to an existing low voltage lighting circuit, it can be prudent to downrate the fuse so as to limit the consequences of a faulty bulb.