Ya can't doo it, Captain! I have nee got the POWER!
Just for the record, I'm not a Gps expert and not an electronics nerd, but the recent advances in technology do make it neccessay to take even more crap on a trip. I've chosen to use my SON Dynamo to power my gadgets (and not a nice shiny easy to steal solar panel).
Gps
After the initial joy of getting a GPS it quickly becomes apparent that it isn't as easy as you think. The guide book that comes with it is as thick as a bible and just as difficult to understand. A GPS is like a mother in law, initially your very nice to each other and very polite, later the misunderstandings start, you dont listen to it when it tells you something, because you assume its wrong and your right. Then the long silence starts, followed by a little give and take, talking, then slowly you start to accept each other and respect the others point of view (however obserd it can be).
I see many advantages to a GPS but often its just a heavy battery slurping bike computer, but I'm still going to take it with me to Africa (because I'm assuming by then we'll understand each other and I won't need to throw it out the attic window in frustration).
Power
I have one of those beautiful SON(schmidt) hub dynamos, its not just there to look pretty and make my wheel strong, its also to power my headlight and charge my gadgets. It is one of the most efficient Dynamos on the market running at about 65% efficency, and when not in use only has about 0.5W drag/resistance. At higher speeds it can deliver up to 6W/12v which will cost about 10W of leg power, which is anywhere between 3-10% of your pedal power depending on how strong you are....
How do I power my GPS with a Hub Dynamo?
I've chosen the to convert all that wonderful hub power to something useable via an E-werk transformer. Copy/paste their sales pitch "
"- voltage (up to 13.3 V) and current (up to 1.5 A) are set in small increments so that all mobile phones, GPS, radios etc. can be powered or batteries charged while cycling, without unwantedly high currents or voltages causing damage to connected devices
- negligible idle losses (only 0.03 W at 30km/h)".
Yes that means you have to set it up right manually or you'll blow your nice expensive I-phone up (so be warned).
The cunning plan!!
This is how I plan to keep my gadgets (mobile, ipod, gps, torch) all powered up through Africa. I use the E-werk to power my Varta usb battery charger
The joy of the Varta is not only can you charge it with USB (I also have a wall adapter), you can also use it to charge USB gadgets. So basically I plan to charge everything up once a week at a hotel/guesthouse, then after that I can use my hub to trickle charge the batteries in the Varta or directly feed my GPS (I still have to play around a bit and find out which works the best), and use the Varta to recharge my mobile/ipod when its needed.
All nice in theory in Europe and on good roads, I'm not sure how efficient it will be on bad roads cycling at 8km/h all day.
UPDATE: I've done some testing recently and the ewerk powers my gps from 7 k/hm 8 if the headlight is on. I feel no real extra effort either, so at the very least I can run my gps full time without using up battery power, now test the battery charger....
There are many other products on the market, but I think this is one of the more efficient set ups. B+M are a German company that make great stuff, and lets face it, the Germans aren't very good at winning wars but they're great with all things technical.
Please feel free to share your thoughts, but bare in mind I've already bought my stuff and wont be buying anything else now, all my money is reserved for food, beer and visa's for the next 2 years:)
Ipone 4 charging with E-werk: I've had a few emails about this, see the comment from Shane Wheller at the bottom of the page, and his solution to usb power.
