USB charging is nice, but I've already solved that problem.
Kim are you able to share with us all what you believe to be the best way of USB charging. Have you made something yourself? Could you share the plans. This was one of my main reasons for buying this light, so I am now looking for an alternative. I need this for longer Audax rides to charge mobile and garmin 800. Thanks
Yes, I have something I designed myself, which works reasonably well and is very efficient. Unfortunately, it's bulky (I'm using through-hole components on veroboard at present), not remotely waterproof (I can do circuits, but good plastic boxes are beyond my skill level) and doesn't incorporate a cache battery (my old phone didn't care about intermittent charging power, but my new one does, so I'm currently using a naff no-name battery pack). And perhaps more critically, due to the usual problems of obtaining niche components in small quantities, it doesn't work out all that much cheaper than a B&M e-Werk. Designs are currently scribbled on the back of an
envelope couple of datasheets and in my head. Drawing something coherent for publication is somewhere way down my to-do list, so realistically don't hold your breath.
If I were starting from scratch now, I'd probably go for a light with charger built-in. It really does seem like the most elegant approach, given that the lights will contain most of the required electronics already. Failing that, the e-Werk seems to be the best of the current crop of dedicated chargers. Actively avoid the Dahon ReeCharge, and any DIY instructions that don't take proper off-load voltage limiting precautions - they're going to cook their own regulator eventually.