Apostate Project

Found out Friday that I am not limited to 28 amps.  Seeing 50+ at times and long strings of 45 amps. Not good when your motor is rated for 28!  Trying to figure this out, everything is kinda on hold for now.

Video of Raging Amps:

When things go wrong during testing

Video Link:  (Its a 5mb WMV)

BadDay

I am realizing how much “engineering” is an iterative process.  I think the motor mount took three times, the “dashboard”/camera mount has probably closer to a dozen, and I am even up to a third “dragstrip”, this one I think is long enough, flat enough and close enough for all tests.

Here is the latest dashboard arrangement.  And I finally got the ammeter wired in.  Of course, it tells me that the controller is NOT limited to 28 amps like I thought it was.  All this time.  DOH!

Runs with the original sprockets (11 front, 72 in back).  These were done on my first dragstrip.

Conclusion:  for the same power, voltage is better than amps.  Of course, I need to run this out a little further and with the ammeter on.

Got the controller linked to the PC – Finally!  How did I do it?  Switch computers.  Still can’t get the controller to talk to the laptop through the USB.  So I brought my desktop downstairs because it has a COM port.

Went out today to try and take data.  As a data system I am using a camcorder, a GPS and a volt meter.  Well, I am * trying * to use.  Need to get rid of the ball head mount and solidly mount it so it doesn’t wander off due to vibration!  But getting closer.

And she will hit 20 mph limited to 28 amps.  Eventually =)

Managed to go a few miles and record the voltage drop vs mileage.  Was going 10-15mph, fairly conservative to not melt the motor.  She’s not getting enough cooling behind the batteries.  And I still haven’t done anything with the controller programming.

I also measured the amount of energy it took to recharge the batteries.  0.32 kWh.  Or 59 Wh per mile.  Although this is also a bit conservative since I had a few rides before I started checking the miles!  Will repeat this when I get a chance.

And before I charged the batteries I wanted to see how they compared to each other, ie would I need a BMS?  They came out like this:  12.32, 12.18, 12.18, 12.30.  Within 1% of each other.  Doesn’t seem like a BMS is needed right now.

Still haven’t figured out the controller configuration program, but I did a slow (right hand limited) trip over to Steve’s.  1.2 miles round trip.  Batteries dropped from 50.9 to 50.2 volts.  So 4-5 miles should be possible with these batteries.

Ammeter is here, and I need to wire it in.

This Week (9/14):

• Mount video camera
• Wire in Amp Meter
• Program controller to limit amps

11:70 Ratio Tests

• 48Volts 28Amps Test Runs
• 48Volts 14Amps Test Runs
• 24Volts 28Amps Test Runs (will solenoid work?)
• Range test
• Wh/mile tests

18:70 Ratio Tests

• Change front sprocket
• 48Volts 28Amps Test Runs
• 48Volts 14Amps Test Runs
• 24Volts 28Amps Test Runs

24:70 Ratio Tests

• Change front sprocket
• 48Volts 28Amps Test Runs
• 48Volts 14Amps Test Runs
• 24Volts 28Amps Test Runs

Charts

• Speed vs time for all three gear ratios
  • Compare top speed and acceleration
• 48V14A vs 24V28A for all three gear ratios (separate charts)

Ok, stiffened up the “design” for the mount, and its slideable so I can tension the chain for different sprockets.

Mount # 3

Also got the Kelly Controller adapter in:

RS232 adapter and cable

Busted!

Busted the new engine mount on its first trip.  Popped the chain off, locked the rear wheel and had to walk home!  Back to the drawing board.

Sprocket from McMaster are here!