Charging Electrical Stuff on Tour

I toured for 3 months with a SON28, Theplug II and Dynamo lights front and rear.

It was enough to continuously power my iPhone 5 which was mounted on the bars and using the MotionX app for mapping and pre-downloaded maps/route. I switched off the screen when I needed to conserve battery or charge faster. A sometimes forgotten point is that you don't need network reception or data connection for the GPS on your phone to work - so you can switch off cellular/data to conserve battery, as long as you pre-download the maps.

There was not enough power to charge the phone and have the lights on at the same time, so if you plan to do a lot of night riding then you'll need additional power. I also used a USB battery and charged it at campsites which I stayed at every few days - mostly i wild camped. The extra juice was used when I wanted to do other stuff on my phone when camped for the night. I needed to charge some hefty DSLR batteries anyway so could not go completely off-grid.

ThePlug II only charges at 500 mA which is a slow trickle - much less than your standard 1amp USB socket on your computer. The B&M eWerk has switchable voltages/currents so you could technically charge those larger batteries, but I'm not sure if the hub can supply that much power at reasonable touring speeds, so realistically if you need to charge at >500mA you'll probably want a solar powered setup eg. Powermonkey.