Bicycle Generators

I slowed down my pedaling as I looked at the charge indicator. My battery was nearly full… and there we go. I dismounted, took the cable for my cell phone, and plugged it into the inverter.

A bicycle generator creates electricity through pedaling. In other words, you are the power source. 

While such a generator will not power your air conditioner (unless you are Lance Armstrong), it will power small electronic devices, such as a cell phone, tablet, or flash light, which can be a literal lifesaver after a major event such as a hurricane or earthquake.

What You Need

• Bicycle (Remember those bikes you scavenged? One of those is perfect for this.)
• Base (I like a bike stand that allows the back wheel to spin freely) 
• Electrical generator (I like to use a car alternator) 
• Board
• Strap
• Car battery
• Inverter like this one
• (optional) an inexpensive multi meter to use as a charge indicator.  

How to Build It

1. Secure the bike to the base. 
2. Connect the alternator to the battery, like you would in a car. 
• If you are worried about this, pull an alternator from a junkyard car and cut off the wiring adapter with about three inches of wire at the end.
• When you get home, look up which wire is which, and splice it in using electrical tape. 
3. Bolt or screw the alternator to the board. 
4. (optional) Hook up a cheap multimeter and use it as a charge indicator.  The voltage on the battery increases as it is charged.
5. Do the same to the bike stand. 
6. Run the strap (often just a couple of old inner tubes stitched together) between the bike and the alternator, around the back wheel.
• There should be some tension on the strap, but not so much that it bends anything. 
7. Bike like it is your only way to watch cat videos. 

http://www.instructables.com/id/How-To-Build-A-Bicycle-Generator/

If you'd like pictures, follow this Instructable link. Note that if you use an alternator instead of a motor, you don't need to add the diode.

How to Use It
When you are ready to charge your device, connect the inverter to the battery and plug your device into the inverter. You can keep biking to charge your device directly, or let the energy stored in the battery do that for you.