Chris' EV Bike - 08/20/05

Inspiration, tired of funding terrorism.

A portion (some say 6%) of the petrodollar flow supports otherwise unproductive people to spoil our picnic. Whatever we do to cut back reduces the misery in direct proportion to our efforts.

Discussion group where I got started.

The bike of choice is a used 24". Used, because nice new things are more likely to "disappear" and that is not an attribute I wish to pay for. 24" because it is almost the same as a full size and a lot easier to stuff into a car. I am 6' tall and raised the seat enough to feel comfortable. I play a 3/4 size "child's" guitar for the same reason.

Original bike with rear carrier added. WE also provided a carrier so I didn't need this.

Original - note unique pedal, kickstand and frame in case of theft.

Plans include a WE BL36 front wheel motor, a KC65 solar panel and various fuel cells. Check back here as I update this page.

08/23/05 x-mas day 2 boxes arrived by Fed X. The larger obviously contained the wheel (and everything else except the battery pack). The battery pack was equally heavy and could have drop shipped from another location. It was assembled w the canvas bag. I greatly appreciated the fact that they used recycled, busted up styrofoam chunks and that no part of the (already low) price went into purchasing NEW styrofoam chunks and fancy packaging. Now I was ready to install a new tire and tube but discovered that I needed a protective "liner", the rubber strip that goes over the spoke nuts and protects the tube from abrasion.

Wheel and tire to be mounted.

It seemed prudent to just toss the whole thing in the car and run to the bike shop to have it done right. As it turned out, they used vinyl electrical tape (that I already had)! I also read in one of the posts that there was some confusion as to which way the wheel mounts. No arrow markings were present. The instruction sheet said wires exit down from the left fork for this "pedal 1st" motor. The ends of this wheel's axle are machined into rectangular keys that must fit into the fork's open ends, kind of like a wrench on a bolt. We want the wheel to spin, not its axle. Furthermore, the fork must not be a "lightweight" type, aluminum, or unable to handle the torque stresses this motor will produce. Failure could be most unpleasant.

After a little struggle, the wheel is mounted.

Don't omit this part. It wasn't included and the wheel FELL OFF at a later date. Once in place, I hooked everything up and ran the motor with the bike on its back to verify direction (ok). The motor and batteries add about 30 lbs which is about what I could stand to lose. I will work on it. The motor is rated at 400 watts, a little more than a half horsepower. Lance Armstrong is said to be equivalent to half of this. I would be doing well to put out about 60. With perfect illumination, the KC65 could provide this in realtime. The motor needs to be in motion at about jogging speed to "kick in". It is a brushless design and has 10 or 12 poles from what I have seen in discussion groups. The permanent magnets are so strong you must have special equipment to assemble/dissassemble the mechanism. The web site shows a 12-pole, 3-phase motor generally wired as a delta.

About to try it out.

It moved too fast for the wifey to get an action shot. I stalled out here so she could get it.

Coming up a small hill. Look Ma, no feet!

After another 15 minute ride, the charge was still full. I hooked up the charger and saw 41 volts open circuit and 1.4 amps into the battery pack. Tomorrow, I will open the battery pack to obtain the two internal series jumper connections. The KC65 will charge one 12-v battery at a time, round robin style. The KC65 is capable of more than twice this charge rate but under most conditions I don't expect this to be a problem.

08/24/05 The battery pack was reasonably easy to open. The batteries were strapped together with the electrical middle battery at the end. My only mod was to attach a short cable to access the middle battery terminals. I sort of wish I used fuses but the way I did it minimizes the impact of a short. They didn't fuse either. I use phone wire for almost everything and double up as needed for current. I also use RCA connectors a lot. The tip is always more positive than the ring.

Inside the batt pack with my wire attached.

I was deliberating with myself as to how to switch the KC65 from battery to battery and decided to forget relays (use power) and DPDT switches (possible short with symmetrical design or asymmetrical arrangement). The simplest and most elegant (read cheap) method uses a cascade of RCA connectors that represent each of the 3 batteries. I can just plug the KC65 into each one round robin and change every 10 minutes or so.


Connections. The jacks are mounted on insulating plastic.

Installed and awaiting the KC65.

The KC65 is a brand new design and should arrive this Fall. The predecessor, KC60 is unavailable.

Temporarily using a smaller 12-watt panel SPE-500.

9/5/05 - Studied the possibility of generation. I connected a full-wave rectifier for 3-phase using two standard bridges. At cruising speed (with controller turned off) I saw about 20 volts rms at 30 hz. That would come from 300 rpm with 6 pole pairs. It would need to be stepped up to charge the 36 volt bank. Standard transformers may not work well at the low frequency. I lit a standard double filament taillight bulb (I'd say about 30 watts) to full brightness under pedal power with little noticeable drag. This would suggest that it might be fairly easy and worthwhile to recover 300 watts when rolling down a hill.

Three-phase rectifier.                     

I noted strong AM band interference to my pocket radio when the controller was turned on and the throttle was actuated.

11:30 am - I returned from a round trip 5 miles each way with essentially no pedaling except for startups. I didn't count but estimate about 1 startup per mile traveled. The return trip took 23 minutes and the bike was getting sluggish during the last mile. The green "full" led was still lit and I measured 34 volts on the battery pack. One significant climb each way was the Alt 19 road overpass at Curlew Road. The trip was from my home to Schiller U and back. It normally takes 15 minutes by car. It took 23 minutes returning by e-bike averaging 13 mph. The bike weighs 70 lb (with the 30 lb motor and battery) and I weigh 175.

It has been charging at about 1.4 amperes since I got home at 11:30. It is now 2:45. At least 4.55 of the rated 7 amp hours had to be replenished. At 4:10 I noticed it was fully charged. It might have needed 6.54 ah.

Assuming the overpass is 30' high, the work for each climb was 30' * 245 lb = 7350 ft-lb. Converting to newton-meters, we have 9958.5 joules. This works out to 2.77 watthours = .00277 kwh. The battery capacity of 7 amphours at 36 volts is 252 wh or .252 kwh or about 2 cents worth of commercial electricity. Climbing the ramp both ways without pedaling used 2% of the battery capacity. This is truly astounding! Is my math correct?

10/13/06 - The bike got rained on and the wheel motor seized up with rust. I ordered a puller tool but was able to get the motor apart before it arrived. Note the two scratches at 3 o'clock.

Mark casing for reassembly.

I squirted lots of wd40 and followed up with chain lube to protect the inside.

Rapped on table to free stator.

10/23/06 - Not long after the repair the wheel CAME OFF while riding. This could have been much worse. The motor, in supplying several pounds of thrust at the rim is twisting the axle with a hundred inch-pounds or more.

Bent tines from very high torque.

I added these. They were not supplied, or on the original bike. You may have to drill them out a bit. I still don't know what they are called.

Don't omit this part.

Next Project - Solar E-Trike

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