Advertise on Bikeforums.net



User Tag List

Results 1 to 3 of 3
  1. #1
    Senior Member
    Join Date
    Apr 2012
    Posts
    92
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    9.6 or 4.8V 5 watt bulb for flashlight

    Living in a well lit city, I need a very bright light. My eyes are adjusted to the street lights and when trees are blocking the light, I can't see the road ahead of me. The streets are often poorly maintained and hitting an unseen pothole or other road problem can be hazardous. I also don't want to spend a fortune on a light and I want to use standard batteries (AA). I currently have 2 el-cheapo LED flashlights mounted to the handlebars, but they simply don't put out enough light or a wide enough beam.

    SO I have a great idea. I have a standard plastic everready 2 D cell flashlight. I want to replace the bulb with a 9.6 or 4.8V (9 or 12v would probably work fine) bulb, cut the flashlight just below the switch and mount it to my handlebars with 2 hose clamps and use a 9.6 (8 AA cell battery pack) or 4.8 (4 AA cell battery pack), both of which I already have along with the chargers. Dewalt makes a 9.6V bulb, but I don't know if it will physically fit inside of the head of the flashlight and I don't know how many watts it uses, just that it says it's 150 lumens.

    Does anyone know of a 5 or 6 watt (or so) standard flashlight bulb incandescent bulb that will fit in the head of the flashlight? My 4.8 battery pack is 12 watt hours and I have 2 9.6V 10.5 watt hours. Both would provide 2 hours of lighting at 5 watts, which would satisfy my needs. I am working on a shoestring budget and this is the best idea I have come up with.

    Also, what about Krypton vs Xenon vs halogen?


    Chris

  2. #2
    Senior Member
    Join Date
    Apr 2012
    Posts
    92
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    This is an update, also from a different part of the forum, so it's a duplicate post.

    So I finally came up with a solution that I hope will work and I only spent $3.50. I had an old Everready flashlight 2 D cell with a standard el-cheapo bulb. So I bought a Maglite bulb 5 cell C/D LMSA501 The info I found on it was this:

    LMSA501 is 6.0v, .92A, 5.5W, 3100K

    But the package says 5 Cell, so I assume it wants between 7.5V-5V (the range of voltage from new to dead of 5 D cells), so I put the bulb into the flashlight, drilled a hole in the bottom of the flashlight and soldered a positive lead directly to the bottom of the bulb and drilled another hole and soldered a negative wire to the neg contact on the switch and took an 8 cell AA holder, shorted 2 of the cell spots and am running 6 AA 2500 1.2V for 7.2V and around a .3C draw off of the batteries, which should be fine for NIMH ULD cells.
    I only have 2 concerns, 1 is that rechargeable cells tend to come off the charger at 1.6V and then fairly rapidly drop to 1.2 and stay there for the majority of the discharge, so this would put the initial voltage right off the charger at over 9V, which I am not too happy about. The other thing is the heat from the bulb. This thing is bright, but then it's winter and I will only be using it at night when it is even colder.

    As for light, it's great. It throws a mean torch even in well light areas, which is one my primary problems. If you don't live in the city you won't get this, but the streetlights are very bright and then when you are under a tree you can't see anything because your eyes are adjusted to the lights of the streetlights. With the streets being in such poor condition, it becomes dangerous.

    The flashlight is attached to the handlebars with 2 hoseclamps (interlocked, one on the flashlight and one on the handlebar) and since there are no batteries in the flashlight, it's really light so I don't see any problems there.

    Has anyone tried anything like this? Also, I have it aimed very low because it is really bright and I don't want to blind drivers.

    If anyone wants to see pictures, I'll be happy to upload a couple.

    Chris

  3. #3
    Senior Member
    Join Date
    Apr 2012
    Posts
    92
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    So I finally got a chance to use this setup in pretty dark conditions and it really worked well. I could see MUCH better. The only thing I don't like about it is that the focal point of the light is about 25 ft in front of me and rather narrow. Also, if I could find a cylindrical battery holder for C cells, I would be happier because I am using the bottle cage to attach the battery holder to the bike. Also, I found an old black flashlight, so I am going to change it out because the one I am using is light blue and my bike is black so it won't stick out so much (kind of ghetto). Ideally, I'd like a better way to attach it to the bike, but for now, it's working. It was 10x better than the LED flashlights. Also, I'd rather be using NiCads because they have such low internal resistance and they perform very well when a high load is put on them and are deeply discharged. NIMH cells have higher internal resistance and the voltage tends to drop if too high of a load is put on them. but AA NiCads simply don't hold enough watt hours. At 1.2 watt hours per cell, I would only have 7.2 watt hours in a 6 AA cell NiCad battery.

    Chris

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •