Any thoughts?
Lots! I've got a
major post upcoming that will include some things apparently never done before. It is all coming together at this end -- with sponsorship from some manufacturers who think it has merit -- and I will soon be able to share it with everyone in toto, and crowd-source some elements of it. The components are in-transit now from around the world, and will soon be ready for assembly. I am...excited.
Until then...mystery! If you are on the cusp of buying, you may wish to hold off a but until my post. I will be testing and reporting on the results periodically throughout the Fall, Winter, and Spring, with the big field test coming on my next major desert tour late-Spring 2013.
In the meantime...
I had the SON28 Klassik on Sherpa, and the *New* Son28 on the Nomad. The *New* Son28 has considerably less drag in my coast-down tests, and output to this point is very close, subject to full-load tests.
The SON 28 with the cylindrical hub shell was the standard hub dynamo; more than 60,000 units were produced from 2000 to 2011.
at the end of 2011, it was replaced by smaller, lighter models with spherical case and renamed "SON 28 klassik". The replacements now carry the old name...SON28 and are referred to by suppliers as "the standard" or the "New SON28". In either case, Schmidt refer to the Klassik or the *New* SO28 as the ones to choose if you wish to charge batteries and power accessories. The SON Deluxe has less drag, but just doesn't produce the power necessary to charge and power gadgets -- LED lights only. The SON28 models (compared to the Deluxe) also have wider flanges.
There is a "wide-body" model of the *New* SON28 that uses wider hub-flange spacing. Some folks find this desirable, while others shrug and say it doesn't matter much in reality. From what I've seen, I think it is a little bit easier (more clearance) to mount a spoke magnet for bike computers on the standard model; I have yet to try it personally on the wide-body *New* SON28.
Here's a summary of the specs for each, drawn from the Schmidt website:
KLASSIK SON28
Electric Power: 6V / 3W according to StVZO
German Mark of Conformity: ~~~ K 179 for 26" - 28"
Efficiency: 65% at 15 km/h
No-Load Power Input: 0,5 Watt at 15 km/h
Magnets: neodym iron boron, 26 poles
Connection: 4,8mm flat spades, 2-pin to connect without ground connection
Axle: hollow axle Ø 10 mm, strain-hardened stainless steel
Bearings: deep groove ball bearing 629 2RSH (SKF)
Hub Shell: aluminium 6082 T6
Colors: silver polished or anodized black
Sealing: alloy dust shields, rubber lip seals and pressure compensation system
Spoke Drillings: 32, 36, 40, 48
Weight: 570 g (without skewer)
Warranty: 5 years
*NEW* SON28
Electric Power: 6V / 3W according to German government's road traffic regulations StVZO
German Mark of Conformity: ~~~ K 834 for 16" - 29"
Efficiency: 65% at 15 km/h in 700c-wheel
No-Load Power Input: 0,5 W at 15 km/h in 700c-wheel
Magnets: neodym iron boron, 26 poles
Connection: 4,8 mm flat spades, 2-pin to connect without ground connection, (special design without connectors)
Axle: hollow axle Ø 10 mm, strain-hardened stainless steel, (Center Lock, rotor mounting system licenses by Shimano: aluminium 7075 T6)
Bearings: deep groove ball bearing 629 2RSH (SKF)
Hub Shell: aluminium 6082 T6
Colors: silver polished, anodized black or red
Sealing: alloy dust shields, rubber lip seals and pressure compensation system
Spoke Drillings: 32, 36
Weight: 440 g (6-hole: 460 g, Center Lock, rotor mounting system licenses by Shimano: 430 g)
Warranty: 5 years
DELUXE
Electric Power: 6V / 3W according to German government's road traffic regulations StVZO
German Mark of Conformity: ~~~ K 687 for 16"-28" (400-716 mm) in combination with Linkhinweis Edelux
Efficiency: 65% at 15 km/h in 700c-wheel
No-Load Power Input: 0,4 W at 15 km/h in 700c-wheel
Magnets: neodym iron boron, 26 poles
Connection: 4,8 mm flat spades, 2-pin, to connect without ground connection,
(special design without connectors)
Axle: hollow axle ø10 mm Aluminium 7075 T6
Axle Ends: stainless steel
Bearings: deep groove ball bearing 629-2RSH (SKF)
Hub Shell: aluminium 6082 T6
Colors: silver polished, anodized black or red
Sealing: alloy dust shields, rubber lip seals and pressure compensation system
Spoke Drillings: 20, 24, 28, 32, 36 (radial lacing permitted)
Weight: 390 g (without skewer)
Warranty: 5 years
Do note I have yet to get a solid determination as to whether the *New* SON28 has the same output as the old Klassik SON28, as that is determined by current-load measurements which I have yet to perform.
Ian, you asked two additional questions -- one about solar+batteries, and the other about an intermediate battery like the e-werks.
Let me address each in turn...
First, I think solar holds much promise, but in terms of practical use
in my own circumstances, it is not quite there yet compared to the output of running hub dynamos. The strength and limitation of dynohubs is they produce electricity so long as you keep going, at the cost of some drag. That is also their downside. The strength of solar cells is so long as you can expose them to sufficient amounts of light, you have "free" power, but -- in the physical sizes suitable to carry and fasten onto bicycles -- the electricity produced is relatively small. Efficiency does fall off with heat (sunlight = heat), and a number of solar cells require a "pre-soak" in sunshine to "get up to speed" before a load (charging duties) is applied. Some do not require a "pre-soak", but they are more costly. Solar works best if the cells can be tipped perpendicular to the sun; tracking arrays are most efficient (Bosch's recent experiment with pedelec touring in Mongolia proved this decisively), but impractical for fixed installation on bicycles that twist and turn with the roads.
I think solar works best *either* powering small AA/AAA chargers or the like, *or* trickle-charging a larger buffer battery. For that matter, a buffer-battery works nicely with a dynohub for the same reasons, and brings me to your second question.
Ian, the e-werks is a charger that attaches to the dynohub. The issue gets a little confusing because B&M also produce a small buffer battery for use with the e-werks and it is sold under that same series name. The e-werks buffer battery is best-suited as *either* a buffer to prevent your gadget (phone, GPS) from going into fall-back hibernate mode when you stop pedaling *or* as a relatively short-term battery-backup, rather than for major storage as with, say, a PowerTraveller PowerMonkey or PowerGorilla or Brunton high-capacity buffer battery. Even those batteries work best by starting out with a full charge and then topping-off from mains sources when you have a rest break -- at a restaurant or overnight hotel stay. Where I go Out and Away for extended periods, I do not have ready access to the mains and the batteries will go down more quickly than my ability to recharge them, given my lower daily mileages in really rough terrain.
At present, the SON28 (either Klassik or *New*) works well for me with the Tout Terrain The Plug2 and PAT (Power Amplification Technology) cable that lowers the speed at which full USB output occurs. In this case, "Full USB" refers to a nominal
5.0-5.5vdc@0.5A. That means you'll have no problem recharging any device that can be charged from a computer's USB port (or equivalent). If your device uses a USB port on a wall-wart plugged into mains power (usually 1.0A output), then you can expect charging times to pretty much double when plugged into either the TTTP2/PAT or a computer's USB port.
At present, I use the SON28/TTTP2/PAT combo this way:
= Eneloop USB AA/AAA recharger to charge the high-capacity Eneloop batteries needed for my GPS, bike LED blinky, (human-worn) LED headlight, AM/FM/Weatherband radio, and my SteriPen water purifier.
= The GPS can be powered directly off the TTTP2 in real-time with fallback to AA battery operation when I pause or stop, thanks to some careful configuration of the Garmin Spanner software on my Oregon 400T GPS; the batteries cannot be recharged in the GPS.
= The GoPro HD Hero2 batteries are recharged in the camera via USB cord; I carry a few spares in case I need to film more than one battery's capacity.
= The Panasonic Lumix TZ-5 digicam uses a Chinese clip-on charger powered by USB cord to keep my spares up.
= The Panasonic 2-head electric shaver has an embedded battery that charges through a patch cord I made myself. The shaver holds a charge for a month that is good for two weeks' shaving if you're fairly speedy.
= My cellphone (a Kyocera SE47 "dumb" 3G CDMA model with superb "reach") uses a homemade USB patch cord to recharge batteries in the phone; 2 hours is good for a couple weeks' standby in urban areas. In remote regions, I usually leave the phone turned off, since it will switch to battery-sucking full power in an attempt to reach distant towers or go into continuous search mode when it can't. I carry charged spares to swap in, since the phone is an essential piece of safety gear for me and is required for periodic check-in to home/friends with my GPS coordinates. If I don't, then after three days a search plan is put into effect via email, phone, and paper packet to the relevant authorities in the area where I am expected to be by itinerary and past check-in.
All works well at present, but it would be nice to reduce my small-battery spares a bit. What would really upset the apple-cart would be a high-drain/high Amp-draw device like a tablet or netbook. That would require More Power, and that gets expensive.
Hope this helps.
All the best,
Dan. (Arrrgh! More Power!)
"If some is good and more is better, then too much is just enough" - Carroll Shelby, American race driver and car developer on horsepower.
"Speed is just a question of money; how fast you wanna go?" - original Mad Max movie.
"Generating power by bicycle is expensive; moreso with more power. How much can you afford?" -- Danneaux.