A reply to Bill's and others comments. I am in the Marine
LED business, so I think I can comment. Yes, you absolutely get what you pay for, as long as you understand what it is you need to be looking for in LEDs. Some folks sell cheap
LEDs to unsuspecting boaters at high prices! Everything Bill says is correct. However, recent advances in thermally-efficient substrates and SMD LEDs have allowed very high outputs without the bulky heat sinks. At least to the extent that you can get the same output as a 10W halogen without exceeding design parameters of the LED. The newest high-output LEDs create less than half the heat at the junction compared to those of just a few years ago.
Here are a few rules for marine
LEDs. I have a white paper (LED for dummies) that I can send to anyone that is interested.
1. Ballast resistor controlled LEDs have NO place on a boat (for very many reasons, least of which is they are not as bright, and won't last the summer)
2. At least 90% of the LEDs sold to boaters are ballast resistor type (which is why many major marine retailers don't carry LEDs anymore)
3. The best LED luminaires are bin selected for color temperature and forward voltage (and UV output) Bin selected LEDs are way more expensive than orphan LEDs, and make for a much brighter lamp (as the can all be driven with the same current). If the supplier doesn't know what binned LEDs are, or can't explain it, keep shopping
4. Marine LEDs must have a constant-current DC/DC converter drive to be efficient and give maximum brightness. If the bulb doesn't list a voltage range something like 8V-30V, or the supplier doesn't know what a PWM DC/DC converter is, or can't explain it, keep shopping
5. Cheapo bulbs can give off UV and cheapo drive electronics
can create RF/EM interference
. Additional electronics
can solve these problems ($). Look for a CE rating. Look also for an RoHS rating (lead-free) if you believe in a greener world.
6. Be cautious of lumen ratings. The best of class
surface mount G4 LED clusters in warm white are at about 50 lumens/watt. While LEDs themselves can be rated higher, right now, when you put them in a cluster and consider the heat issues, electronics, and the packaging issues of the g4 form-factor 50/lumens per watt is about it. Measuring Lumens requires a integrating sphere and expensive equipment
, so if the vendor is hip shooting Lumens and wattage, it is usually easy to smoke him out.
Watch for Practical Sailor's LED test in the November issue for a test of marine LEDs. I haven't seen the results, but I suspect that we will see that all of the companies that come out on top are owned by cruisers, and meet the criteria above. I suspect that all will be >$25 a piece as well. Also watch for the preview in Annapolis
and then the introduction
of a real-world 90 Lumen per watt G4 replacement with no heat sink and in an easy to fit form-factor. Hard for even me to believe, but it has some slick technology.
I will be in Annapolis
with my new 120 Lumen G4s (no heat sinks or crazy wire pigtails). This bulb has no peers to the best of my knowledge, and is significantly less expensive than "the other guy"
Contact me if you will be at the show, and I will be happy to give you a real world demo.
Because this is not a commercial
forum, I am not including links, etc. I will be happy to continue discussions at the request of the members.