You need:
- 1x Motorcycle
- 1x Soldering Iron
- 1x USB Cigarette Charger
- 2x Cable Ties
- Light Wire
- Fine Sandpaper
- Screwdriver / Allen Key Set
- 2 Hours
So last month, I needed to mount a USB power supply on my bike (Yahama Fazer) to run the GPS (Navigon) on my iPhone without the battery dying before I reached the end of the driveway. So I installed a USB cigarette charger to run in parallel off the side light circuit. It worked great, and now I arrive everywhere on time with a fully charged iPhone.
First thing to do is to get your hands on a USB cigarette charger like this one. €8 in Maplin. For an iPhone, you could always just use the Apple charger, but the USB one gives you the freedom to plug in other devices. On most bikes, the light circuit is 5v so there’s no need to step the voltage. If you do need to, good luck mounting a transformer under the fairing (which could really unbalance your bike).
The connection in the center of the charger is your live (+5v), and connection on the side is your negative. So get stripping & soldering (if you don’t know how to solder, here’s a video. You may need to use fine sandpaper to roughen the surface of the connections on the charger to get a good contact when you soldering on the wire. Throw a multimeter onto the wire and the charger to check the joins are good.
Once you’re done soldering, use heat shrink tape, or something similar that will last, to wrap around the joints between the wires and the charger. This will just add extra strength to the joints for those heavy wheelie landings.
To get access to the light circuit on the bike, you might have to remove some of the fairing. On the Fazer, the light circuit has a slip on connection which you can pop off easily. Cut the circuit, strip the wires and tin the ends. I used a plastic connector like this one to add the charger in parallel with the light. If you don’t have a connector, you could solder on the wire from the charger. Again, check all the connections with the meter, it’ll be a pain to fix once it’s all mounted.
If you’re happy everything, give it a trial run on the bike. The charger I bought had a LED power indicator which I used for testing instead of frying my iPhone. There’s no app to tell you your iPhone’s dead. Once tested, mount your creation.
Find a good dry spot under the fairing to mount the charger. If you don’t have a fairing, you might want to get a weatherproof container (also in Maplin). Sorry about the crappy pic, was working late.
Find something secure to tie the charger to. Use a couple of cable ties for this, and give it the wiggle test. Once you’re happy, find a way to route the USB cable from the charger to your GPS/Phone/Whisk/Etc. Make sure you allow enough give in the wire for turning the bike (I forgot this and nearly broke the charger – slap). Test again, wrap everything up if you’re happy and enjoy! On the Fazer, the side lights are always on when the ignition is on.
I bought an iPhone mount from the UK, can’t remember the site off-hand, but mail me if you want me to dig it up for you, and happy riding!