White LED Flashlight Conversions

Many flashlights can be easily converted to use white LEDs instead of regular incandescent bulbs. The flashlight can quickly be returned to its original bulb and battery configuration later if you wish. Of course this procedure will void the warranty on your flashlight, but the only permanent modification made is increasing the size of the hole in the reflector assembly. Since I live in a remote area with no streetlights and am a volunteer firefighter, flashlights are very important and are used daily by everyone in the family. I normally use Maglite® flashlights in different sizes for reliability reasons, but have been frustrated with short battery and bulb life. I normally get only 5 hours on 2xAA batteries, and have to change bulbs every 2 sets of batteries or so. Converted white LED MiniMaglites® have become my favorite flashlights! Though the LED conversions are not as bright as normal bulbs, the batteries last over 6 times as long, and I have not replaced an LED bulb yet despite running them at over their maximum current. Otherpower.com sells super-bright white LEDs that are perfect for flashlight conversions, plus LED clusters that fit normal automotive taillight bulb sockets, available at any auto parts store. We made various attempts at figuring out how to mass-produce the spacer with resistor -- and we've decided not to offer them for sale because we can't manufacture them cheaply. Much better to make your own anyway! You can check out our line of efficient lighting products in the Renewable Energy section of our web shopping cart. MiniMaglite® LED ConversionsAlkaline batteries are often the best choice for flashlights, since they retain more power when sitting unused for long periods of time. And you can expect over 6 times longer battery life when using a white LED bulb! This is important when a flashlight must sit in your truck for weeks or months without use. In this situation, NiCad or NiMh rechargables would most likely have little power left in them after sitting for months. Alkaline N-cells are inexpensive and usually locally .

 Take off the flashlight head and remove the incandescent bulb. Save the bulb for future use if you ever decide to return your flashlight to its original condition.  Trim the tabs off of the LED leads using nippers. A flat needle file or sandpaper can help smooth the lead.  Trim the LED leads off to 1/4 inch in length.  Insert the LED into the bulb socket. If does not light up, reverse the LED and it will. If not, check your batteries, and also make sure the LED leads are not touching each other.  Remove the reflector, and using a 1/4 inch drill bit carefully widen the hole for the bulb to 1/4 inch. Our LED bulbs do not need reflectors since they emit light at a set 20° angle, but the reflector assembly is needed in a MiniMaglite® for the switch to function properly. Now try your flashlight with the original AA batteries. It should light up, but somewhat dimmly. If you run it like this, the batteries will last for weeks of continous on-time. It's not very bright, but it is enough light to find the keyhole or make your way to the bathroom. To run the LED at full brightness you'll need to use 3 N cells. Next,  Install the 3 N-cell batteries.  Install a spacer (containing an internal current-limiting resistor) You'll need to build a spacer to hold the resistor and make the whole battery pack come out to the right length. Our prototype used a 3/8 inch length of 1/2 inch diameter wooden dowel (see photos below). We drilled short holes at the ends of the dowel for battery contacts made of small machine screws. We then drilled an off-center hole all the way through the spacer for the resistor, and wrapped each resistor lead around the contacts.