Sturmey Archer HDS22 Dynohub 12V Setup

Discussion in 'Lighting and Electrical' started by Tony01, Mar 9, 2018.

  1. Tony01

    Tony01 Active Member

    Nov 28, 2012
    Likes Received:
    I want to share my 12V charging setup that I've been testing for a few months. I saw this setup in the thread Sturmey Archer X-FDD Dynohub/Drumbrake Experiments by Bairdco and decided to try it out.

    I bought the hub for $45 shipped off ebay. Not only a dynohub, it is also the cheapest sealed bearing disc hub on the market at this price. Spec for this hub is 6V 2.4W, however the drum brake hubs all seem to come with 6V 3W dynamos. I didn't get a choice, and a look at their website seems to show that the dynamos in the disc hubs and non-brake hubs are all 2.4W.

    [​IMG]Dynohub 12V charging system

    The Setup:

    Sturmey Archer HDS22 disc dynohub. 6V 2.4W, 36h, 100mm spacing 9mm solid axle, 6-bolt ISO disc.
    Husky 26x50mm steel rim
    CST Cyclops 26x2.4 front tire
    Husky 10g spokes 10"
    Pitbike 12V regulator/rectifier 4-pin
    Autozone 12V LED flood light
    12V LED side marker red light

    The hub is laced with 10g spokes into a 26x50mm Husky steel rim, with a 26x2.4" tire on it. The wire connector on the hub is a small plastic piece that slides on the tab with the two terminals, holding the wires connected by friction. One of the hots is grounded to the axle, so it needs to be connected to ground on the frame somewhere.

    A small 12V regulator/rectifier from a pitbike is next. This is a 4-pin. In a pitbike it typically runs off a stator with two hots plus ground, but here we only have the two hots with one of them being a ground. So we are only using 3 pins. If we look at the R/R with pins 1-4 going clockwise from upper left:

    p1: 12V+
    p3: GND/AC-
    p4: AC+
    R/R housing must be grounded to frame (bolted)

    Here you can see the connections: p3 wire mini-harness connecting Batt-, AC-, and frame GND, p4 dynohub+, p1 battery+ and lights. The battery is always connected to the regulator, the lights are switched.

    [​IMG]Dynohub 12V charging system

    I was able to tuck the regulator in between the head tube gussets with a single 1/4-20 screw. The right side gusset has a hole for an allen wrench.

    [​IMG]Dynohub 12V charging system

    Riding it
    Sounds about right; P.out directly proportional to speed. Riding it with a dead or low battery at night shows exactly what is going on without a voltmeter. Turn on the lights at a stop and they glow dimly, the lights start strobing brighter when you start moving, and they are very bright above "slow motor speeds". With a fully charged battery, there is little to no strobing. My battery is beat up and doesn't take or hold charge well. However, I have found that going for a long day ride (over 20mi) charges up the battery sufficiently to not drain much running at night.

    Overall, this is a very clean setup that works 100% and has made night riding possible and hassle free. I will take strobing any day over having to charge the lights battery on the bike.

    Make it better

    Still reading? Run a nice high Ah lithium battery and a switch. Fab up a hook and rubber strap setup to make battery removal a breeze. :D
    If I was gonna do this again, I'd build a 24" front wheel with an alloy rim, 14g or 13g spokes and run the XL-FDD.

    If anybody wants a setup like this, feel free to contact me.
    #1 Tony01, Mar 9, 2018
    Last edited: Mar 9, 2018
    PeteMcP and bairdco like this.

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