Originally Posted by propellanttech
It's really hard to find a good quality LED in the market now.
I would probably buy a replacement from a marine
The others are probably repackaged off brand name.
This is not true at all. No offense but I work in the industry and parts
are fine. In fact boat stores gouge prices up too high. Also a led is typically hermetically sealed so salt
should not work it's magic on the little device.
LEDs have specifications that have to be meet in order for proper operation. As someone briefly mentioned above, the led has a voltage drop and a current rating that you'll need to know in order to keep it working for life.
First the equation for selecting a proper resistor (remember resistors limit current if installed in series, so no burning out LEDs)
(V - veld) / currentmax = resistor
Vled is the voltage drop the led will need
12 v battery
2 vled ( specified on data sheet or box that led comes in) most are around 2 volts
20 ma (also specified on box or data sheet)
this into the equation and you will get the needed resistor to be soldered in series with the led.
If your battery level is not constant then take the highest voltage and use that in your equation. Also this is not rocket science so as long as you are conservative with a resistor selection it will work fine. I say a 1Kohm resistor should be fine for most LEDs for boats
I hope this helps.