How warm do LED lamps?
I am trying to install a pair of 12v led lights in series for headlights. The lights work great, but the housing they came with was junk-- would never keep out water. My plan is to mount them inside an old 6 volt flashlight housing where they will be fixed in place by packing them in with some sort of material.
I would like to use styrofoam (lightweight, shock absorbing and form fitting) to pack the flashlight, but I have no idea whether the lights will get hot enough to melt the styrofoam and whether they need air exchange to dissipate heat (won't be available sealed up inside a plastic flashlight housing.
Most LEDs powerful enough to perform as headlights produce enough heat to require cooling by some means. Styrofoam is a heat insulator, and is likely to cause OVERHEATING of your light, with eventual destruction of your light. Normally, 5 watt LEDs would be requred for such use, and they should be attached to a suitable heatsink for cooling, if sustained operation is required.--Be advised that homemade headlights are NOT usually approved for roadway use, and if an accident were to occur related to this un-approved lighting system, you could be found to be "At Fault" and in a undesirable legal situation. You could lose any lawsuit, or be held liable for damages.--Bob
You'll also notice that most LED bulbs sold for headlights or even lightbulb replacements are shrouded in a giant heat sink. It's not there for decoration.
Sometimes its a good idea to not re-invent the wheel. Depending on the legal class for your ride, there are some great aftermarket lights and light systems available that will light the path effectively, and are well engineered. Yes, they may cost, but the headaches (or eyestrain) it may save you may be countless. For e-bikes, There are LED, HID, and even Halogen sets that outperform these little lights. Is a good light worth the couple of hundred you could spend?....Would you ride in the daylight blindfolded? You may still have to use your creativity on the mount, but at least once placed, you will be able to see. As usual, check local laws and ordinances for your vehicle, and proper placement. Helmet lights do not legally replace vehicle equipment requirements. If your bike light meets the legal requirement, maybe a helmet light isnt a bad addition. As far as brands go, NiteRider, light & Motion, Marwi/Union, CygoLite just to name a few.
Another thought on the recycled 6 volt flashlight.... most reflectors are not designed to get maximum illumination from the forward facing design of LED's. The ones that are getting any brightness to them at all are a surface mount design and there is next to no side view capability to them for the reflector to use, as they'd sit so far back from the filament bulb focus point. The tradeoff for illumination is heat, so they do have to breathe, as they are semiconductors. Breathing and massive heatsinks.......