New Project: Bike Powered Generator

So here's my new 4 stage project: Take some bike parts and some car parts, and put them together to make some electricity. This is not a new idea. It's not even that original. Pretty much everything I aim to do, has been attempted and done before, just not by me. Hopefully, Stage 4 will be where it really opens up into new territory, if I make it that far. Jim and I have been talking about doing this for somewhere close to 2 years now. In that time, a lot of the things we've talked about have been done by other people. Each time we come back to the topic, we learn a little more and it gets a little closer to reality. This time the topic came up, something sparked in my brain and it's time to execute on it. I have come up with some basic guidelines to take me forward:

1. Spend $0 on new bike-specific parts. My bin runneth over already.
2. Spend as little as possible on the electrical parts.
3. Stage 1 must be completed before messing around in Stage 2, and so on.
4. Power must be usable, to get out of Stage 1, the system will have to measurably produce full power for an hour of riding.

I should probably outline what I'm hoping to accomplish before I get too far down the line. Stage 1: Working stationary bike that is capable of producing usable 12v electricity and storing it in a battery. Looking to create a sustained 80w of power at this point. Hopefully 100w, but we'll have to see how efficient of an alternator I can get for cheap. This will require some parts and materials some of which I have, so I will have to scrounge:

• 12v DC alternator
• 12v deep cycle battery
• Wiring in various gauges and terminals to connect them
• Drive belt
• Nuts/bolts and some parts to mount this up to my stationary trainer
• Ammeter to quantify the output

A few days ago, I pulled an alternator and battery from a junk 1988 Dodge Caravan that my dad had sitting in the farm yard. It's a 3 wire, 75 amp aftermarket alternator for that van, so I'm hoping it's good and efficient. The battery is not a deep cycle battery, but it was also an upgrade for the van, a Die Hard that will do 800 cold crank amps. Eventually, I'll need to swap the battery for a deep cycle version so it can take repeated charges and discharges. Last night, once I figured out what the heck the wires were all for, I hooked it up in about 15 minutes, with some seriously half-assed connections.

My brother-in-law Jared helped me hold the alternator pulley against the rear tire on my trainer while I pedaled. I had a multimeter set up to show voltage. While powering the alternator field without movement, the volts were down just above 2v (battery had been sitting for a long time unused), I started pedaling, got it up over the 1800rpm range, and the voltage spiked up to a full 14.4v which means the alternator was then successfully powering itself and beginning to charge the battery. So with Stage 1 solidly underway, now comes the more serious business of cleaning up the wiring and mounting the alternator solidly to produce a constant level of power output. So here we go.