We have found a specific defect in "headlights" using LEDs.

At the Winfield (WVA) Festival, all "vehicles" moving around the campground at night are required to have head and tail lights. Since virtually no "mobility scooters," and relatively few golf carts, are "natively equipped" there is a need for small light units that can be temporarily (but securely) mounted to meet the requirement.

Having tried more than a dozen mostly deficient "installations" on our mobility transports, I've noticed that NO LED LIGHT among a dozen I've tried permits distinguishing between wet grass and standing water in a mud puddle. The reflectivity of both, for available LED wavelenghts is identically zero so you can't tell which you're approaching.

Since mobility scooters can usually pass through wet grass fairly safely, but are PERMANENTLY DEAD if the controller (invariably mounted beneath the floorplate) gets any liquid water on/in it, this becomes a very important factor in what's an acceptable headlight.

Two years ago, I bought an $800 "emergency replacement" for LiK's scooter (used and with broken parts, original list $1280), when she hit an inch of water in a puddle. After two years of searching I think I've found a source for a replacement controller, but some additional research on details is still needed. (It was a better scooter, so repair may be merited.

There has also been a recent report on a common hazard from LED devices. In order to produce the "white light" desired, or even some red beams, the usual method involves producing of "invisible IR" or sometimes UV light to "pump" the visible red and/or "white" lasers. Specifications for blocking the UV side emissions from the "output laser" generally have been followed by manufacturers, but a significant number of "low cost" devices have been found in which no IR or far UV filter appropriate to the "pumping laser" was included. The "pump" emissions are at a level that can fry your retina and cause permanent damage to your vision.

This latter problem probably wouldn't apply to one of the $150 headlights being seen occasionally now (he says, optimistically believing in the NHTSA), but the adspeak doesn't clearly indicate spectral outputs adequately to assess whether the water/grass (and other features one might want to distinguish) contrast is really satisfactory.

John