1st Phase - Project E - Bike

After reviewing my future plans and considered income level I have figured that it will be several years until I have the space and finances for a full scale EV - project. This is rather dejecting. The idea came to me however that I could probably begin doing other projects on the cheap. After reviewing Oregon's driver laws, I discovered that electric bikes require neither registration nor insurance - but are limited to 20mph and must be pedal powered in addition to any electric motor. This handicaps, while strict, shouldn't be to much of a burden for a project bike. So the adventure begins!

My plan is this: I have little funds, so I am going to try to keep the bike as low cost as possible. I plan to utilize Craigslist's "free" section and the Yahoo freecycle group as much as possible. I should be able to find a free bicycle or at least put one together by the end of the month.

Others have tried similar projects in the past, and are excellent references. It seems that a starter motor for a passenger vehicle (1 - 1.4 kw, 12v) paired with a 12V battery will do the trick. Some have tried upping the voltage to 24V, but this is generally not a good idea (damages motor, battery, potentially even wiring due to over amp-ing). Since electric bikes in Oregon are required to have pedal power anyway, the system might as well be used as an assist for the electric motor.

The nice thing about using a starter motor is that they are relatively cheap and extremely easy to find. My hope is to snag one for free but I would still be willing to pay a few dollars. I have a shopping advantage in that it doesn't really matter which motor I get.

Batteries are going to be the difficult part. Traditionally e-bikes have been equipped with lead - acid (car) batteries, but these are large and heavy, and often make the rider sit in funny positions. I would prefer to employ lithium ion, an expensive and powerful substitute. Currently A123 systems makes Li Polymer packs which run on ebay for 10$ each. I figured for my system I could use eight of these, packing them into two packs and running those packs in parallel, giving me 13.2 nominal volts and 4.6 Ah, with constant current draw of 140 amps! The whole deal would weight ~ 600g!

For throttle a simple switch is often used but I would like to construct my own variable current model. I imagine a couple of copper plates in a modded gripshift could accomplish the task - more on that later.

Locomotion will travel through a double freewheel hub, with a single speed on each end. This way you can coast off the pedals and throttle, plus you can combine the two energy types. Such hubs are available at 50$ online - and unlikely to be found free on craig'slist. Same goes for the single speed freewheels (25$ each).

So, budget for my-first-electric-bike:

Donor Bike - free
Starter Motor - free
Extra chain - free
Gripshift - free
A123 Systems batteries x8 - 90$
Double freewheel hub - 50$
Dual single speed freewheels - 50$

I don't know the cost of copper wire, leads, or other electronics I will certainly need, but I don't imagine they will be difficult to purchase. I also am not sure how I will mount everything, but that is for another post.

Why EV?

In 2007 I retired from the military and sold my car. I had to pay for insurance, parking, license fees, and gas, which was getting too expensive, and since I didn't need to get to the Nation Guard Armory anymore, I decided to let my ride go. I also have a notorious dislike of ICE vehicles (that's Internal Combustion Engine) for their emissions and dependence upon non-renewable resources. To be short, I loved that car but I didn't miss it.

Fast forward to 2009, and I find myself wanting a vehicle again. I want it for different reasons this time, namely racing and not commuting, perhaps autocross. It wouldn't be a problem if it weren't for the fact that most production cars are still ICE. What's an eco-conscious budding "Stig" to do?

The answer is the EV, or Electric Vehicle. Essentially, it's a car powered by an electric motor. The EV is as old as the ICE is, but with a higher energy density they've been kept off the market. With oil disappearing fast and battery technology improving however, the tables are turning.

An EV powered by an electric socket which derives its energy from wind and/or solar would be the a true zero emissions self propelled vehicle. That is a concept that I can live with. Unfortunately, road worthy EV's are few and far between these days; and even then most are tuned towards efficiency and look rather ridiculous.

I want a car that I can use to whip about on the weekends and perhaps even autocross. Even if the GM EV1 ever made it into production, it wouldn't be the car for me.

Luckily Tesla Motors has decided to change that. Their new roadster has shown me that EV's can be sporty too. This beast hits 60 in 3.7 seconds and can outperform its cousin the Lotus Elise! This power comes with a price (100,000 to be exact), but a price worth paying.

While I'm not ever going to have the cash on hand to afford such a super car, I would be able to settle for something a bit less showy. Backyard EV conversions have been going on for decades, and it's process that really excited the mechanic in me. I would much rather build a car than buy it, and a quality EV conversion can cost as little as 20,000 USD!

Thus I have given myself yet another project: Once I have the assets and workspace, I will begin constructing an electrical monster to tear up the race track - or at least the motorway. Stay tuned to this blog for updates on my project.