Dynamo light + dynamo GPS (or phone) charging. Bye-bye batteries?

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  • Dynamo light + dynamo GPS (or phone) charging. Bye-bye batteries?
  • smudge
    Member

    Excellent work Rob, Ive been following your blog and i’m very impressed with what you have been doing. Keep it up 8)

    robdeanhove
    Member

    I’ve finally got my bike set up with a dynamo powered LED light and charger and I’m super chuffed with it. Now I’ve been riding it a while and am happy it’s all working reliably, I thought it best to share:

    The power from the SP PD-8 hub can be switched, via a little switch on the bars, from the front light to a USB carger, that happily charges my GPS or my smart phone, while they’re on and working and faster than they use power.

    The cockpit setup:

    The USB cable can also be used to charge my joystick head torch if needed for multi-day rides involving camping.

    Power is provided by a tiny, light weight dynamo hub from Shutter precision:

    The light is a pre-production (available soon) Exposure dynamo light, with off-road-capable standlight. The standlight also powers the rear light, which is the standard, and well proven, exposure redeye should you want one for the on-road sections:

    FRONT LIGHT

    REAR LIGHT

    The charging can then be done by one of the many dynamo chargers available on the market, which just attach to the main power cable from the hub. Most of them come with selectable outputs either to the light or USB plug, to keep the intervention required to install it all minimal.

    Forseeing the nay-sayers, here’s a couple of FAQs I answered earlier:

    1) So, dynamos are heavy, right? No! The Exposure light comes in at a flyweight 112g, with the SP hub another 390g, A total weight of 502g. Yes, a MaXx-D is only 337g, but you still need a front hub, and with a Hope Pro 2 coming in at 190g, that’s a total weight of 527g, 25g heavier. And that’s without factoring in having to run my battery light on a low light setting or the weight of carrying alkaline batteries as spares for the GPS or some form of battery charger.

    2) Isn’t a dynamo draggy? Well, Please excuse the maths, but if you rode at 20mph for an hour the light would pull about 6W from your legs during this time, this is equivalent to approximately 5.2kcal. There are approximately 72kcal in a McVites Digestive biscuit, enough to power your light for just under 14hrs and that’s assuming you pedal down the hills and around every corner! So yes, it does draw a tiny bit of power, but I certainly can’t tell the difference and it’s a damn good excuse to eat an extra biscuit every few rides 😉

    There’s a bit more detail on the details of my setup, and some pretty pictures of my bike and the rather special wheels Reynolds helped me out with ON MY BLOG HERE (CLICKY).

    Enjoy….. Dynamo power FTW!

    robdeanhove
    Member

    Excellent work Rob, Ive been following your blog and i’m very impressed with what you have been doing. Keep it up 8)

    Cheers Smudge! I hope you get the chance to be equally impressed with how the dynamo light behaves on the trail 😉

    Premier Icon jameso
    Subscriber

    Great post. I really like that system, now if only there was a 135mm option to fit my fork (

    damitamit
    Member

    Nice setup!

    I got a pv-8 built into a lightweight road wheel last week. A23 hub and 24 Sapim Lasers. Used it on the Dunwich Dynamo this weekend with a B&M Cyo and was brilliant.

    One question, when you spin the wheel by hand (with the light off) do you find it stops very quickly? Or is this just mine? My shimano alfine dynamo hub will spin for a while like this.

    CraigW
    Member

    For dynamo lights and charging, the Axa Nano Plus looks interesting. it is a light with a USB plug built in. http://www.axa-nano.com/

    Those SP dynamo hubs look rather nice. Any reports on long-term reliability?

    robdeanhove
    Member

    Great post. I really like that system, now if only there was a 135mm option to fit my fork (

    There is! You can buy a “clip on” dynamo that attaches to your spokes, that fits any width of frame or fork and can be fitted to the right (non-disc) side of your MTB or the left side of your rear wheel if you’re running rim brakess, i.e on your road bike.

    CLICKY LINK HERE

    For dynamo lights and charging, the Axa Nano Plus looks interesting. it is a light with a USB plug built in. http://www.axa-nano.com/

    Yes, it is a light, but it’s not bright enough for off road, there’s no low speed light boost like on the Exposure model, the standlight only lasts for 4 minutes and even then is a “be seen” light, not a light to see by. Good luck trying to ride on or off road in the dark! That light is intended for “urban” use, i.e. riding on roads with streetlights and the purpose of the light is for cars to be able to see you. Beware: All dynamo lights are not equal! The Exposure light is a genuine replacement for my MaXx-D off road, a massive step up from the normal single LED lights that are designed with town use in mind, where the light output will drop dramatically at low speeds. Oh, and he Exposure light is pretty amazing on road too, of course

    I got a pv-8 built into a lightweight road wheel last week. A23 hub and 24 Sapim Lasers. Used it on the Dunwich Dynamo this weekend with a B&M Cyo and was brilliant.

    That’s because dynamo lights are an awesome solution! 🙂

    The B&M Cyo has a great reputation and having tried a few different LED dynamo lights, I’m sure, on road, particularly in a group, it’s great, and especially while moving at a decent speed, but I’d not want to try and use one off road! Nor alone on a dark country road at night due to the narrow beam, again, this is really designed for town use, but these lights can make good, occasional use touring lights for when it’s getting dark and your day’s taken you longer than you thought.

    One question, when you spin the wheel by hand (with the light off) do you find it stops very quickly? Or is this just mine? My shimano alfine dynamo hub will spin for a while like this.

    Mine spins for “ages”. I suspect rim and tyre weight have a big influence on the time the wheel spins for, as this inertia will be significant. The PD-8 has fewer poles than the shimano hub and is significantly lighter (less than 2/3 the weight!) and, as such, draws slightly LESS power at low speeds (they both produce the same power at riding speeds when connected to the same devices) so the PD-8 has less drag and should spin for longer?

    Those SP dynamo hubs look rather nice. Any reports on long-term reliability?

    I’m running a PD-8 off road and a PV-8 on my road bike and have commuted off road regularly on them and have done multi-day road tours with lots of luggage and even submerged it in water when going through a puddle on a flooded road that was deeper than I thought and they’ve just kept pumping out the power to the light 24/7

    I’ll be using mine for all 1300miles of the EWE without any concern, and the hub has already got quite a few miles on it.

    I hope that helps with at least some of the questions above this post!

    jimification
    Member

    I’ve not been aware of dynamo tech since those terrible old “wheel on the tyre” contraptions but this looks completely sorted. Brilliant that you can use it to charge up other gear. Must be so good not to have to carry tons of batteries for GPS / phone or go off route to find them on multi-day trips.

    Lots of questions spring to mind…Seems like it could be pretty good for 24hr racing too…Is the light unit a standard Maxx-D output? How fast do you have to be going to be able to run it on the brightest setting? (Can you get 1200 lumens out of it?) There’s some sort of small backup battery in there isn’t there? If you brake hard for a corner does the light output reduce instantly or is it somehow stablised by the battery?

    Best of luck in the EWE!

    Premier Icon midlifecrashes
    Subscriber

    Looks brilliant. Good that the LEDs and dynamo tech is coming together well. Are those hubs OK to service/bearing change without too much faff? I guess you’re just the guy to find out in the middle of nowhere. Good luck EWE.

    mcmoonter
    Member

    I just bought a Schmidt hub for my touring bike. What charging device did you use, B&M E-werk?

    I’m keen too to hear your hub works longer term off road.

    bencooper
    Member

    I’ve built several bikes recently with the Tout Terrain Plug2 – it’s a neat little top cap for your headset which has a wire running down inside the steerer to the dynamo, and a USB socket on the side. Very tidy…

    Rik
    Member

    I’ve got a set up very similar to Robs. Pd-8 hub hooked up to a Tout Terrain Plug2 both are great bits of kit and worked really well on the last week long tour in the Hebrides with no external power sources.

    If you plan on using it to power things like iPhones or anything with a high drain I would recommend paying a little more and getting the Tout Terrain Plug2 plus. That had a power booster so it works better at slow speeds.

    robdeanhove
    Member

    What charging device did you use, B&M E-werk?

    The answer’s in the longer, and probably too long for a forum post, full blog post, which is linked at the bottom of the original post

    FULL BLOG POST LINK HERE

    On chargers, I said: “I’ve tried a few different chargers, including the offerings from Softhema, Kemo and making my own. There are plenty more available from other well known brands. They’re all small, lightweight and simple, comprising of just a few components. This is excellent as it makes them super reliable too. In this case I’m using the Softhema offering as it straps most neatly onto my bike setup, with the long thin form factor attaching neatly to the brake hose. A small toggle switch on the bars switches the power between from the lights to the charger so I can use the hub power to top everything up during daylight hours.????”

    The B&M device liiks great but is waaaaay more expensive than I was happy to pay, similarly the dahin device and the Tout Terrain plug, but these offer more functions, such as a battery power cache and lovely package solutions.

    CraigW
    Member

    Yes, it is a light, but it’s not bright enough for off road, there’s no low speed light boost like on the Exposure model, the standlight only lasts for 4 minutes and even then is a “be seen” light, not a light to see by. Good luck trying to ride on or off road in the dark! That light is intended for “urban” use, i.e. riding on roads with streetlights and the purpose of the light is for cars to be able to see you. Beware: All dynamo lights are not equal! The Exposure light is a genuine replacement for my MaXx-D off road, a massive step up from the normal single LED lights that are designed with town use in mind, where the light output will drop dramatically at low speeds.

    I’d agree that Axa light is probably not bright enough for proper off-road, I was thinking more of touring/audax use.
    Its rated at 50 Lux, so I’m assuming it is about as bright as a B&M IQ Fly / Cyo, which have a good beam shape and are plenty bright enough for road use. Including for seeing where I’m going on unlit roads, not just in town.

    Oh, and he Exposure light is pretty amazing on road too, of course

    Whats the beam shape like on that light? Does it dazzle traffic?

    robdeanhove
    Member

    There’s some sort of small backup battery in there isn’t there? If you brake hard for a corner does the light output reduce instantly or is it somehow stablised by the battery?

    No batteries are heavy, have a finite life of only 500-1000 cycles, don;t like colt temperatures and require complex charging and discharging control that puts up cost and complexity at the cost of reliability.

    The Exposure Revo uses some very special indeed capacitors (and some other cleverness) to store some energy and keeps the light running, gently reducing the level to “still really very bright” when you slow right down or even stop for “quite a while” according to my testing i.e. the light stayed bright enough to ride by for long enough for me to eat a cereal bar from my back pocket, look at the map on the garmin, get bored and a bit cold and carry on riding, happy it more than met my needs! I’m sure there’ll be some official stats when the official launch occurs later in the year.

    My advice is, rather than look at the numbers (we all know there’s a world of difference between a 1000lm light from Hope or Exposure and a 1000lm light from eBay), ride one. I was properly amazed that it was a dynamo, having ridden a few of the previous offerings available and rejected them as unsuitable for off road & fast singletrack.

    robdeanhove
    Member

    I’d agree that Axa light is probably not bright enough for proper off-road, I was thinking more of touring/audax use.
    Its rated at 50 Lux, so I’m assuming it is about as bright as a B&M IQ Fly / Cyo, which have a good beam shape and are plenty bright enough for road use. Including for seeing where I’m going on unlit roads, not just in town.

    We’re agreed then, these lights are fine for that use. It wasn’t long ago we were all riding around on the Mk1 Exposure light at ~200lm on full power or with 5W & 10W halogens, marvelling that we could ride at night properly at all!

    Whats the beam shape like on that light? Does it dazzle traffic?

    I believe the beam shape is not managed in any special way for the road, not on the current light I have at least. The beam points wherever you point the light, so you might want to point it more downward for road use, than for off road. This is pretty common except for lights made for sale in Germany, where it’s legislated.

    Having the 80lm redeye rear light makes it a great option for on road use for me, as the safety of a really bright rear light without the possibility of the battery going flat or dimming slowly until I notice on day, is very attractive.

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