Advertise on Bikeforums.net



User Tag List

Results 1 to 4 of 4
  1. #1
    Junior Member
    Join Date
    Oct 2009
    Location
    Wimborne UK
    Posts
    8
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Question Dynamo led light power consumption

    In the old days of normal bulbs they were rated in watts or amps so with a 3 watt dynamo you knew to put a single 3watt front bulb or a 2.4watt front with a .6watt tail.
    Now we have led lights its not clear what the power is so how many lights can you fit to a 3watt dyno?
    I'm running a shimano 3 watt dynohub.
    Last edited by CAPTAINBUGWASH; 11-29-09 at 01:27 PM.

  2. #2
    Zoom zoom zoom zoom bonk znomit's Avatar
    Join Date
    Sep 2006
    Location
    New Zealand
    My Bikes
    Giant Defy Composite,Trek 1.7c, Specy Hardrock, Nishiki SL1, Jamis Commuter
    Posts
    2,804
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You can draw around 10-12W from the dyno with the right circuit. Pilom.com has some data on it. No idea if hooking 2/3/4 commercial lights up together is a good idea, I expect not, but a single triple light is likely bright enough.

  3. #3
    Gear Hub fan
    Join Date
    Nov 2008
    Location
    Reno, NV
    My Bikes
    Civia Hyland Rohloff, Swobo Dixon, Colnago, Univega
    Posts
    2,830
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    From my reading and experience the brighter German street legal lights such as the B&M Lumotec IQ Cyo, Schmidt Edelux and Inoled Inolight Extreme draw between 2.4 and 3 watts. German dynamo lighting regulations specify that these lights must reach full brightness at quite low speeds which limits their allowed power draw. They also have strict regulations on acceptable beam shape for all street legal bike lights.

    Several more powerful dynamo LED lights are on the market which are not German street legal. These include the Supernova lights, the Light On! Dynolight and the British Solidlights unit. These do not reach full output until higher speeds. The Solidlights light is listed as requiring 6 watts input by the manufacturer. The Supernova E3 standard (not the Triple) is noted as drawing .4 watt too much power for German road approval even thought the Asymmetric version now has a German street legal beam shape. Per their web site the Light On! reaches full output at 18 to 20 MPH. Per an email from Supernova their E3 Triple reaches full output at about 25 MPH. I would not expect these to be suitable for multiple installation if hooked up in series for simultaneous use.

    Per Peter White Cycles web site none of the current commercial LED lights are really designed for multiple use. If hooked up in parallel, with a selection switch, the higher power ones could have two installed but not run simultaneously. The lower power lights could presumably be run in series like the old bulb lights but like them would not reach full light output until substantially higher speeds are reached.

    My own choice for a dual LED light installation would be two Supernova E3 Lights set up in paralllel with a selection switch. One would be the asymmetric beam E3 for in town use, effectively giving a low beam, and the other would be the E3 Symmetrical or E3 Triple for out of town and high speed night use.
    Gear Hubs Owned: Rohloff disc brake, SRAM iM9 disc brake, SRAM P5 freewheel, Sachs Torpedo 3 speed freewheel, NuVinci CVT, Shimano Alfine SG S-501, Sturmey Archer S5-2 Alloy. Other: 83 Colnago Super Record, Univega Via De Oro

    Visit and join the Yahoo Geared Hub Bikes group for support and links.
    http://groups.yahoo.com/group/Geared_hub_bikes/

  4. #4
    Commuter JoeSoMD's Avatar
    Join Date
    Sep 2008
    Location
    Southern Maryland
    My Bikes
    Specialized Sequoia Elite
    Posts
    129
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    See the data on the Pilom.com site... I think that the tables below circuit 7 provide the information you are looking for. Here's the link: http://www.pilom.com/BicycleElectron...moCircuits.htm
    =======================================================
    From Miller in Repo Man: "the more you drive, the less intelligent you are."

Posting Permissions

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