LED lights are flickering when the engines are running.

I replaced the engine room halogen bulbs and fixtures with some of those led light strips . The halogens don't respond to the voltage fluctuations but the LEDs do. Is this an alternator problem, or just one of those things one learns to ignore. I figured the house batteries would sort of buffer out the alternator cycles.

Anyway, should I care about this?

Thanks,

Frank

Read up on constant current LEDs, needed for boat type installations. Here is an admittedly self-serving, but accurate white paper by a supplier.

Constant-Current?

f508 said:

I replaced the engine room halogen bulbs and fixtures with some of those led light strips . The halogens don't respond to the voltage fluctuations but the LEDs do. Is this an alternator problem, or just one of those things one learns to ignore. I figured the house batteries would sort of buffer out the alternator cycles.

Anyway, should I care about this?

Thanks,

Frank

Click to expand...

The before reference paper is a good one; but, if my LED's were unstable with the engine on and stable with engine off, I would have some concern.
Engine alternators have 3 phase ac then recified outputs. This should be a fairly clean waveform into a healthy battery system. LED's are optically, very fast devices, and don't have the thermal inertia that an incandescant lamp has.
One engine or two? LED issue only when a particular alternator is running? I'm thinking an alternator or regulator instability, that becomes visible with the LEDs. A good instrument for inspecting your alternator/regulator power quality is an oscilloscope.

I'll get into the LED driver technology if necessary, since I design linear and PWM type power supplies; but, in the end, the battery buss should not have short term instabilities (noise).

Did you get 12 volt leds or 10-20 volt? Leds are very intolerant to voltage and need "buck and boost" circuits to allow for the fact that your boat runs on 10 volts (if connected when you hit the starter) to 15+ while charging (you do disconnect for equalizing?) but 12 to 14.7 or so normally. Check the rated voltage?

They are the 12 volt LED lights that are on the sticky tape. And they are stable with the engines off. That is what I was wondering about. They seem to be sensing a voltage variation from the alternators. Is that normal? I'm not much of an electrical guy, but I thought the house batteries would have sort of "buffered" any voltage variation.

Next time I run the engines I check and see if isolates to one of the alternators.

If you used any of those clip-on connectors on the strip, you could have a bad connection affected by the engine vibrations. I have a finicky one in my home kitchen that I have to fiddle with.

If you have a DMM, a dc and a ac reading may be illuminating.

I've had bad luck with simple 12V strip lighting. In fact all applications have failed in short order. So then I bought a cheap buck stabilizer on line and that failed out of the box. I suspect it would have been "noisy" in the RF sense anyway. My current approach is the flat 12V arrays sold at Menards for $5 that plug into the old puck style halogen fixtures scattered around the boat. They seem to have some built in circuitry...no idea what. But for a five spot, I'll give 'em a shot.

try a simple hash filter for alternators. It will smooth out the output of it.

https://www.google.com/search?q=alt...pL_WAhUN62MKHTvBAC8Q_AUICigB&biw=2049&bih=906

You can "bulk" filter for all dc loads with a big amperage filter, or just filter for the led lights themselves with a lower current and lower cost filter.