Made a handy little "Lifetime" flashlight for my girls to use in our 95 Odyssey for reading at night. We had normal flashlights before but they used up batteries in short order. The special reading lights were cheaply built and broke easily.
Using a halogen bulb, single AA battery flashlight from Target ($1.99), I replaced the plug-in bulb with a super-bright LED from Allied Electronics (#505-3006, http://www.alliedelec.com/catalog/pf.asp?FN=533.pdf) and the AA alkaline 1.5 volt battery with a 3.6 volt lithium (#590-0190, http://www.alliedelec.com/catalog/pf.asp?FN=19.pdf). A 3.6 volt source is mandatory as this is the voltage at which the diode is biased on (turns on). The LED is a low current draw device and the lithium battery last for years, so even if they leave them on, they will not burn out. I expect 4-8 years of use out of them. However, the bulbs are not as bright as a regular bulb but still bright enough to read by.
other ideas: Wire 3 or 4 of these diodes in series to vehicle power and install in the headliner to provide reading light. These diodes are VERY directional (15 deg beam angle) and would not need a reflector to aim the light. Some sort of bendable mount would allow for aiming the beam location.
Using a halogen bulb, single AA battery flashlight from Target ($1.99), I replaced the plug-in bulb with a super-bright LED from Allied Electronics (#505-3006, http://www.alliedelec.com/catalog/pf.asp?FN=533.pdf) and the AA alkaline 1.5 volt battery with a 3.6 volt lithium (#590-0190, http://www.alliedelec.com/catalog/pf.asp?FN=19.pdf). A 3.6 volt source is mandatory as this is the voltage at which the diode is biased on (turns on). The LED is a low current draw device and the lithium battery last for years, so even if they leave them on, they will not burn out. I expect 4-8 years of use out of them. However, the bulbs are not as bright as a regular bulb but still bright enough to read by.
other ideas: Wire 3 or 4 of these diodes in series to vehicle power and install in the headliner to provide reading light. These diodes are VERY directional (15 deg beam angle) and would not need a reflector to aim the light. Some sort of bendable mount would allow for aiming the beam location.