Condensation - Why Does It Happen
Condensation happens when the outside of the lens is cooler than inside the lens. When you drive around with lights on for a few hours, the bulbs warm the air inside the headlight lens. The same thing could happen when the headlights sit out in the sun all day.
So now the air inside the headlights is warm. If you turn your lights off or pull your vehicle into the shade, there will be a large temperature difference between outside and inside the lens. The cool air wants inside and it begins to sneak into the tiny vents that are found on most headlights. When that cool air meets with the warm, condensation is formed. That happens on the warm side of the lens, so you have got a little layer of moisture on the inside of the headlight lens.
Virtually all lights are prone to condensate due to the following events: Air is trapped inside a lamp when manufactured Plastic parts used in lights naturally absorb moisture in the air As the light heats up these plastics parts release moisture that mixes with air. Moisture attaches itself to the coolest part of the lamp, e.g. the lens Halogen lamps tend to run hot so the moisture evaporates more quickly LED lights produce less heat so moisture takes longer to evaporate, so it can be more noticeable
Condensation vs Water Ingress
Condensation is a naturally occurring condition that can affect any light. It does not suggest a defect in a product, as opposed to what happens when a leak occurs, in which case there is water ingress that could lead to a system failure. The explanation contained herein is intended to help end users differentiate between these two conditions so they understand what, if anything, needs to be done.
Condensation does not cause a problem with normal operation of the light and is, therefore, NOT considered to be a defect or warrantable condition. In fact, Eagle Lights are designed to allow moisture to escape and not reenter, but it takes time for the moisture to evaporate (the amount of time will depend upon whether or not the light is turned on or not).
Sources of water ingress can vary. If a light suffers water ingress as the result of physical abuse and/or misuse, it would not constitute a manufacturing defect. Otherwise, water ingress caused by a defect in workmanship is a warrantable item. In this event, please contact the dealer who supplied the product to schedule a return.